On illegal hits: Heap shot no cheap shot?

Kam Chancellor's huge hit on Arizona Cardinals tight end Todd Heap during the Seattle Seahawks' 13-10 victory Sunday drew a 15-yard penalty for unnecessary roughness.

"It was as clean a hit as you can get," Seahawks coach Pete Carroll told reporters Monday.

I've been going through the rulebook and replaying the hit before making a judgment. I've also watched again the video NFL officials showed to players differentiating between illegal hits on defensive players and hits delivered within the rules.

Carroll appears to be right. I can't imagine what officials could have instructed Chancellor to do differently.

Heap was taking an angle on Seahawks safety Earl Thomas during Thomas' interception return. Heap's head was turned back to Thomas, who had not yet passed him, when Chancellor drove his shoulder into Heap's shoulder area, flattening him. Chancellor did not launch himself through the air at Heap. He did not strike Heap in the head or neck area.

Chancellor's play was similar to the block Chicago's Earl Bennett put on Seahawks punter Jon Ryan last season. The NFL video prepared for players shows Bennett's hit as an example of a legal play.

"Nice adjustment made here to play within the rules and avoid blowing an opponent up," NFL executive vice president Ray Anderson says while narrating the video.

Cardinals coach Ken Whisenhunt wasn't asked about the block on Heap during his news conference Monday. Carroll said he thought players, coaches and NFL officials were going through a transition period figuring out rules changes and points of emphasis.

"I saw a hit on a little recap game where a quarterback was running -- I think it was (Drew) Brees or something -- he was running and he got pounded as he went down," Carroll said. "It looked exactly like helmet-to-helmet and they waived it off as no penalty on the play because the quarterback was still trying to make yards. ... I think everybody's trying to figure it out the best they can."

Two hits on NFC West quarterbacks did not draw penalties when I thought they should have, but as Carroll said, some of these situations are difficult to interpret.

On one, Cincinnati's Nate Clements struck San Francisco's Alex Smith with a helmet-to-helmet hit. On another, Cardinals defensive end Calais Campbell picked up Seattle's Tarvaris Jackson, then slammed him onto the turf with great force. Upon consulting the rules, though, protections against plays such as the one Campbell made seem to apply only to quarterbacks while throwing or right after throwing.

"A rushing defender is prohibited from committing such intimidating and punishing acts as 'stuffing' a passer into the ground or unnecessarily wrestling or driving him down after the passer has thrown the ball," the rulebook states in part. "When tackling a passer who is in a defenseless posture (e.g., during or just after throwing a pass), a defensive player must not unnecessarily or violently throw him down and land on top of him with all or most of the defender’s weight. Instead, the defensive player must strive to wrap up or cradle the passer with the defensive player's arms."