This is the same Adam Schefter who tweeted Harrison was likely to be fined for an alleged hit during the Steelers Week 9 loss to Baltimore.
Despite the report, Harrison did not receive a fine - or a penalty - in that game.
The play drew a 15-yard penalty - Harrison's first personal foul penalty this year, and first since Week 10 of the 2010 season. Including the playoffs, Harrison hadn't been flagged for what the league views as an illegal hit in 16 games, including the playoffs. That number does not count the games he missed this season.
Under NFL Commissioner Roger Goodell, two players have been suspended for on-the-field actions; then-Titans DT Albert Haynesworth, who stomped on the face of helmet-less Andre Gurode, and Lions DT Ndamukong Suh, who stomped on the arm of a Packers lineman and repeatedly slammed his head into the ground.
Both players were ejected from the game. Harrison was not.
Suh had been fined multiple times this season for his on-field conduct, and openly disputed the fact a penalty was even called. That led to the Lions issuing a public statement condemning his actions.
If consistency counts for anything, Harrison's penalty is not worthy of a suspension. It's hard to call him a repeat offender, considering he clearly has adjusted to the league's sudden emphasis on helmet-to-helmet contact.
The play in question has McCoy out of the pocket and scrambling forward. The ball is tucked in his arm, thus making him a runner instead of a passer. Harrison breaks down (gets in a stance to deliver a hit on the ball carrier), and moves toward McCoy. At that point, McCoy flips the ball quickly to his left. Harrison continues through the hit, and strikes McCoy with his helmet.
A penalty is valid in this case, because NFL rules state the onus to stop and prevent the hit when the quarterback no longer has the ball is on the defender. However, a suspension in this case would be unprecedented.
Harrison viewed McCoy as a runner, and not a quarterback. Helmet-to-helmet penalties are called on quarterbacks and defenseless receivers, not runners. It's extremely difficult to argue McCoy was not a runner when Harrison first attempted to hit him, considering he was outside the pocket and was running. Harrison should have held up and not struck McCoy, according to the rules of the game, but some credence should be given to the speed in which McCoy changed back into a passer.
The actions that occurred on that play are within past examples of a fine, not a suspension. Harrison's play has been clean in both the eyes of the game officials (no flags) and the league (no fines). A suspension seems over the top, and certainly something Harrison should appeal, with the full support of the NFL Players Union.