MacTavish was fined for remarks made following Friday night's 3-2 loss to the Dallas Stars.
"The NHL acknowledges the fact that referee Mick McGeough made the wrong call on a play late in the game, which he later admitted to the media following the game," director of hockey operations Colin Campbell said in a release.
"While the NHL regrets the missed call, Craig MacTavish's comments after the game regarding the call were totally inappropriate and crossed the line."
McGeough called off Ales Hemsky's goal with only seconds left in the third period. He had blown the whistle a heartbeat before on the faceoff, convinced that Shawn Horcoff had made a glove pass off the draw. It was something the replays showed did not occur.
"It was a retarded call," MacTavish snapped after the game. "There is no other explanation for it. I know he is a veteran official and at times I have found his antics humorous. But if this is the product of that there is a problem.
"It was a ridiculous call. I had no idea what he had called. Nobody saw the hand pass on the play because quite clearly there wasn't one. It's beyond reason.
"He should be suspended."
Some members of the crowd at Rexall Place littered the ice with debris following the decision.
Hartley meanwhile, was assessed a gross misconduct and fined $10,000 for verbal abuse of the officials at the end of the Thrashers' 4-3 victory over Washington on Friday night.
The money from both fines will go to the NHL Foundation.