What's the story behind Belichik and Mangini?

I read the article and I agree. But how would you feel if your buddy's team tampered with your Super Bowl MVP reciever. This screwed up the Pat's season as they have a bunch of scrappy recievers trying to fill his role. You don't expect a friends team to do this to you. I believe this had a moderate impact in BB's attitude towards his ex coach EM.