Colleague blames me for not spotting typos when I only reviewed the structure and content I am a graduate student (PhD) in a STEM program.  A fellow lab mate of mine asked me to review a chapter (basically the background/history of their project) of their graduate thesis a couple months ago.  It was during my finals, I had conference papers due, along with the pandemic shutting everything down; it was a crazy time.  I informed this person I was really busy, but I would try. They sent it to me (in PDF format), and I read through it and made some suggestions on content, ideas, and presentation. It was in rough shape; there was a lot of work to be done, but their main concern was if the content made sense and had good logic flow.  I replied with my opinions. This was a favor from me without compensation. The thesis was in English and the lab mate was a native speaker.
Fast forward to now, this person defended their thesis this week and passed.
Yesterday I received a very passive aggressive text message from this person that stated the following (mostly paraphrasing):

The only real critique I had on my thesis was that the chapter I sent you had typos.  I went through this chapter again and found quite a few.  In the future when someone asks you to review a chapter you need to carefully check and find typos because it’s embarrassing to send a final thesis with a chapter filled with typos.  Its disappointing when you rely on someone and they screw you I hope in the future you do a better job.

The rest of the text chain did not go well.
Let me start off by admitting that I am able to see my fault in this.  I could’ve (should’ve) done a more thorough job in editing.  But my question is: Is it really my responsibility to find typos? It’s always been my view that you polish something as much as you can before sending it off to others. They sent it in a PDF which I can’t edit (also no indication of spelling mistakes, and its so easy to gloss over mistakes), and I informed them I was super busy, both excuses, but still a little relevant.  I also was dumbfounded that they didn’t do a single edit after mine.  I feel ultimately it is their graduate thesis and their responsibility for its contents.  I feel I can’t be blamed for this person literally not pressing the spell-check button.
In hindsight I should’ve been more assertive with this person by saying I didn’t have enough time to fully give myself to editing.  This is a lesson I’ve learned.  They are now removing me from their acknowledgements (I couldn’t care less), but what I do care about are the things they are telling other people about me (I screwed them; I’m lazy; etc.).  I replied to their texts expressing my view that the typos are not my fault, and it quickly turned into a blow out where I just ended up apologizing and asking not to discuss it further.
What could I have done better? What should I do now?  Am I justified in my opinions?
PS:  Thank you all for your responses and encouragements.  I was feeling pretty bad about the situation, but I feel a little vindicated now.  I’ve learned a lesson: I will focus on clear communication and setting expectations.
&quot;The only real critique I had on my thesis was that the chapter I sent you had typos. I went through this chapter again and found quite a few. In the future when someone asks you to review a chapter you need to carefully check and find typos because it's embarrassing to send a final thesis with a chapter filled with typos. Its disappointing when you rely on someone and they screw you I hope in the future you do a better job.&quot;

This is unfair. What happened was, at best, a miscommunication on their part. They somehow thought you would check thoroughly for typos, which you did not have time to do. Unless you told them &quot;this chapter is perfect and doesn't need more editing&quot;, I have trouble imagining why they would assume the chapter was camera-ready.

Let me start off by admitting that I am able to see my fault in this. I could've (should've) done a more thorough job in editing.

I don't see that as a flaw. If anything, perhaps you could have communicated more clearly about what you were able to do, as well as what you did not do (thoroughly check for typos).

I feel ultimately it is their graduate thesis and their responsibility for its contents.

Exactly right, and this is truly the &quot;bottom line&quot; here. No one else is responsible for the content of your thesis but yourself. Getting help does not absolve you of the responsibility to proofread your own document and when you defend, you are supposed take full ownership over what is written.

what I do care about are the things they are telling other people about me (ie I screwed them, I'm lazy, etc).

The word for this is &quot;bullying&quot;. This behavior is not acceptable and should not be tolerated by you or anyone else.