You've got to trust your mates, if they are saying you were fine (but blattered) then you were most likely fine.  Remember, mates love give each other a hard time when they do something, you would have heard about it. 
And, remember, what's done is done, there isn't any changing anything in the past.  I still deal with replaying scenarios in my head and getting quasi panic attacks but they are just what you describe them as: intrusive thoughts. 
The mind is a seriously complicated and messed up thing.  It can fabricate memories out of nowhere that you know are 100% real.  Try to look at these situations and think about them in a joking/stupid way.  "Yeah, IMAGINE I did that! lolz".  Making fun of the intrusive thoughts is something that I have found to work personally. 
Your are right tho, this is a fantastic thread.