Let's look at this play rationally for a second.
Flagrant foul? Most definitely. Stevenson hit him across the face. Inadvertent or not, you can't do that.
But a punch? LeBron has got to be kidding himself. DeShawn hit him so hard that LeBron didn't even fall down. Look at the end of the last replay. It's a bit fuzzy, but DeShawn's hand is open-fisted.
And as for DeShawn jawing after the play ... well, LeBron clearly marched over to him as he was on the ground. What else is DeShawn supposed to do, run and hide?
Then, there's Mike Brown. He's clearly instigating things when he runs across the court in order to scream at the officials. Notice the beginning of the replay. He doesn't try to break up the scrum. The only thing he does is run to the officials.
The Wizards have been outplayed in this series, but this play undermines Cleveland's squeaky-clean reputation. It says something about the effectiveness of their public campaign when they can make this play out to be anything more than a hard flagrant foul.