Roughness call in NFL

[MJT]

I work semi-pro ball, and have an official NFL rule book from an NFL official I know. A couple of things about the NFL rules.

1. ANY player, not just the QB, can give himself up and be downed by purposefully sliding. NFL rule 7-4-1-c states "the ball is dead and the down is ended whenever a runner declares himself down by sliding feet first on the ground. The ball is dead at the spot of the ball at the instant the runner first touches the ground.

2. Rule 12-2-8 on UR states that is is UR to "running or diving into, or throwing the body against or on a carrier who falls or slips to the ground untouched and makes no attempt to advance, before or after the ball is dead."