and the one flag they DID call "unecessary roughness" i believe was on ray lewis for a hit he put on TE Hernandez. As Hernandez caught the ball, he turned and lowered his head. Lewis didn't know he was going to lower his head and ended up making helmet to helmet contact. I don't know if they called that a defenseless receiver or H2H, but the defense was flagged nonetheless.
Now here is the SAME PLAY except the TE doesn't lower his head after the catch, but he is still lit up. Yet no flag.
http://sports.yahoo.com/blogs/nfl-sh...2728--nfl.html
In both cases I don't think there should have been a flag, but in one case there was. SAME PLAYS except in one the TE lowers his head / leads with his head.