AITA here? I feel like I know the answer to this, but knowing what others think helps. TLDR at the end.

I have this friend, John, whom I've been friends with for about 20 years. I talked with a mutual friend of ours, Tom, recently. Tom, who is also a current customer of mine (John brought him to the business) said that John had some sort of break down at his most recent job waiting tables. He kept oversleeping and was missing/coming in late for shifts, so he went on work disability for stress.

Tom said that John blames me for this because after all he did for the business, I forced him out as a partner. I didn't get into specifics with Tom, so I just told him it was either end the partnership or close the business down. Shutting down would cause my customers a good amount of harm because there's a chance they'd incur additional expenses with reconfiguring their current equipment. At the very least, it would be a pain in the ass to switch.

I initially started this business with $40k of my own money. John had no money, but he promised to handle weekly system maintenance, and customer support. I would handle sales &amp; marketing and operations, and we would split onboarding new customers. At the right time, I would get my initial $40k back plus a reasonable % return based on profits. Everything else we would split 50/50 since we split the workload 50/50.

John brought Tom and one other business as customers. I was going through a horrible divorce (to the point where my ex was filing false police reports in an effort to get full custody), and I wasn't bringing in new customers like I needed to. 

John floated the company anywhere from $20-$200 for several months to keep checks from bouncing. All told, his floats totaled about $4k. When I got back on track, I paid John back by giving him a bigger percentage of the fees we charged from onboarding new customers until he was square.

While he was floating the company money, I noticed that John wasn't handling customer support or system maintenance. He wouldn't log into the system for weeks or months at a time, if at all. If customers contacted us for support, he immediately asked me for help. He would say he didn't know the system as well as I did, so after helping him (and the customer) I gave him the resources I studied to learn the system for him to study. He continued to ask me for help every time a customer called, and admitted he hadn't studied anything when I asked him. 

It was a choice between enabling him and helping the customer or potentially losing business. Admittedly, I got upset with him after one incident in which he blew up my phone while I was meeting with a potential client. When I didn't answer, he called the client's office explaining that there was a support emergency and he needed me. He called right when I was explaining to said potential client how stable and reliable our systems were, and how we had enough personnel to handle any problems they had.

After this incident, there were two or three other times where upset customers were calling me directly saying they had sent emails and left voicemail messages several days ago without a response. I would confront John about this, and he said he had responded and left messages, but they never got back to him. He would then immediately contact them with me present and tell the customer he left messages. The customer would then second-guess themselves, and John would end up handling the issue.

About a year after I straightened out my personal issues and after he had been paid back, he was still slacking on his share of work. After another of these complaints, I checked the company email logs. The customer had sent an email that was forwarded to John. However, John had never responded. The only thing I couldn't tell was if John had called the customer or used his personal email address. I then checked the system, and maintenance hadn't been done at that point for about 9 months. I took screenshots and copied logs to document everything.

I took him to lunch and brought up the subject, and I said that I felt like I was doing about 98% of the work but only getting paid 50%. It was taking time away from finding new business, and delaying getting my $40k plus return back as we agreed. John acknowledged I was doing the majority of the work and that he had been slacking, but he said that he floated the company when I was having personal problems. He also said (and I quote), "And how about all of the customers I brought in?"

I reminded him that the company paid him back while I haven't gotten anything beyond distributions. I also said, "You mean Customer A and Customer B? One who's your best friend from high school?" I then proposed two options. 1) we end the partnership now, become competitors, and keep the customers we each brought on. 2) I temporarily take an 80% share, and give back 5% per month to him for every month that he meets work milestones. He could even start the milestone list and be in charge of editing it until we finally agreed on it.

John proceeded to comment that both choices were unfair, and countered with me getting 60%. I said to John that since he acknowledged I was doing about 98% of the work, did he honestly think that I should only get 60% of the profits, and would he agree to that if the roles were reversed? He then said he was only agreeing to option 2 out of our friendship. I wrote up an agreement, we both signed it, and he promised to get the milestone list together in a week.

Two months later, after asking multiple times for the milestone list, and John either saying "next week" or not responding, I got a call from our biggest customer. They had called and emailed three days in a row and nobody returned their call. They called because their service was not working consistently, but now it wasn't working at all. I logged into the system and saw the problem. The particular server's script that clears cache files stopped working, and disk space was almost out. Deleted the cache, rebooted the system, customer's working again.

I checked the system logfiles, and John hadn't logged into the system one time since we switched to the 80/20 agreement. I immediately texted him to call me regarding something urgent about our biggest customer. He called me the next day.

I told him what happened with our customer and that I handled it. He expressed relief and said, "I wish they had called sooner." I said, "speaking of which, I have something to show you." I texted him the screenshots of the system logs, email logs, and call logs, and the list of cache files on the server. I explained that this was what the problem was, and luckily, it was a quick fix. John then said that he couldn't see exactly what caused the problem.

I said that he hadn't logged into the system in over two months. I also said that log screenshots showed that the customer had called and emailed, but they got no response. It also showed that the calls forwarded to his phone. I then said that things weren't working out, and we can't be business partners anymore. If he wanted the business he needed to buy me out of my $40k plus 80%, or I could cut a check for his 20% share so he'd be out. Either way, he needed to decide in 7 days, or I would hire an attorney to figure it all out. I said that I hoped we could still be friends, but I would understand if he didn't want that. John gets very upset, says some words that I don't remember, and hangs up on me.

He texted me the next day saying he was giving up his 20%, and he didn't want any money. He said he valued friendship over the business, unlike me, and that this was all my plan to steal the business from him.

I saved the texts until I sent him an agreement to relinquish his shares and he signed it. Recently, John texted me randomly, saying that he couldn't believe how I could do this to his friend and how he stuck by my side. I said that I felt the same about him: how could a friend promise to do his share of the business but not do any of it? He then responded that I was a dick. I deleted the texts and blocked his number because fuck him.

TLDR: I invest $40k to start a business, close friend invests $0 but promises to do half the work plus allow me to get back my $40k plus return. He floats the company about $4k while I go through personal problems, but stops doing his share of the work even when he gets paid back. I confront him the first time and he agrees to a 20% share, but still doesn't step up to do work. We almost lose our biggest customer, I confront him again and end the partnership. He calls me a dick.