By Michael Hurley, CBS Boston

BOSTON (CBS) — By definition, the penalty for “unnecessary roughness” ought to require some actual roughness to take place. Or so one might think.

The Patriots learned on Sunday afternoon in Miami that roughness is not a requirement for a costly penalty flag to fly.

The instance came late in the first quarter, in a game where the Patriots got out to a brutal start. With Miami ahead 14-0, the Patriots’ defense finally provided a positive by forcing a punt. (Granted, even that positive was muted by the fact that Devin McCourty dropped an easy interception on Miami’s third-down play.)

But the Dolphins didn’t punt, instead opting to run a fake punt on fourth-and-3 at their own 42-yard line. Punter Michael Palardy took off running for the first down marker, but realizing he wasn’t going to make it, he went down into a slide a couple of yards shy of the line to gain.

Brandon Bolden, who recognized the fake punt and turned around to stop Palardy, made a headfirst dive to try to hit Palardy to make the stop. A flag was immediately thrown, as Bolden led with his helmet.

Bolden, however, did not make any contact with Palardy, instead flying over the body of the sliding punter. That didn’t matter in the eyes of the officials.

The penalty for lowering the helmet does actually require contact to be made. Lowering the helmet in and of itself does not constitute a foul.

The rule is written as such: “It is a foul if a player lowers his head to initiate and make contact with his helmet against an opponent. Contact does not have to be to an opponent’s head or neck area — lowering the head and initiating contact to an opponent’s torso, hips, and lower body, is also a foul.”

The Patriots were called for this penalty last week, when Myles Bryant hit a Jaguar after lowering his head.

The rule was made a point of emphasis heading into the season, and the Patriots have been burned by it twice in the final two weeks of the season. The latter instance — which came while trailing 14-0 on the road — was notably more painful.

It ended up being rather costly, too. The Dolphins went on to score a field goal on the drive, after being gifted the 15 penalty yards. The Patriots scored a touchdown with 2:57 left in the game, a touchdown which cut Miami’s lead to three points. They didn’t get the ball back again until 3 seconds remained on the clock, and a lateral gone wrong resulted in a Miami defensive touchdown to make the 33-24 final score seem more lopsided than it actually was.