No i go by the rules, I have played football for 8 years, and watched it for over 25 years. here is the rule
2. Clipping: Throwing the body across the back of an opponent's leg or hitting him from the back below the waist while moving up from behind unless the opponent is a runner or the action is in close line play.
3. Close Line Play: The area between the positions normally occupied by the offensive tackles, extending three yards on each side of the line of scrimmage.
Ok, not clipping. But it was an illegal block in the back, above the waist. Still a spot foul penalty that was missed.
BTW... I wish the entire NFL rulebook were available on the web. The "digest" posted on NFL.com that you linked to is woefully incomplete...