Is AUTHOR wrong in the post ? POST : I have a good friend who is emotionally manipulative, and has just gone through a very hard breakup. The girl will be A, he’ll be L

L and a we’re together for 2-3 years, and L was thinking about getting engaged. A, however, found someone from a sports team L played for more attractive and ran off with him. 

Your probably wondering where this goes, but that will become important.

L is very very strange. He changes emotional state very quickly and uses this to his advantage. 

In the weeks that followed their breakup, i was repulsed with his behaviour: 

He deleted all her insta, snap and twitter posts, then denied it
He put up posters saying “have you seen this t*o*, s*** wanted, matching description of A, answers to Sl**ty McSl**face
He threatens her and in the end it took 4 of our friends to stop him attacking her, and another 2 ( and myself) to calm him down.

I knew none of what I am about to write, which is why I go so annoyed. 

He bought her a £250-£300 gift for her birthday, despite working part time minimum wage at a local restaurant- NOT fast food. They broke up 2 days after her birthday.
He’d payed all the bills when they moved in together despite her having a better job

But I went crazy at him, yelling, screaming, threatening to call the police, the whole shebang. And then he just disappeared. I don’t know where or how, but I know when and I guess his friend yelling at him is why. 

Then, he left the team him and A’s new bf were on, moved apartment and excommunicated all of his friends  and relatives. I later found him and gave his address to all his friends, and we helped him through.

But my question is, Am I the Asshole as he had trust issues and his friends were the only support he had, despite 2 sisters, a still living parents and grandparents. And I let him down.