[Did he really need to address the elephant in the room? The one biggest fuck up he's done beyond killing his allies (friends?) as a machine. Not really but... This was Hank he was talking to, prompting him to be a bit more honest.]

Hank... I heard the gunshot outside of your house...

[And that's the thing that really makes him hate what happened out of everything. There's a lot of shit to be mad about, but knowing he was partially responsible his death...]

I never want to relive that again, even if it was just a "what if" scenario that never happened.