Think by the laws of the game its a yellow. But as others have said, in my opinion those sort of tackles where there's no attempt to play the ball and there's some sort of lunge should probably warrant a more severe punishment than your usual 'take one for the team' pull backs etc. An orange card perhaps.
I know it doesn't work like this, but anywhere else on the pitch that tackle is a yellow, counter attack or not. The fact McCann is breaking away should be considered an aggravating factor, as it is its own yellow offence.
Really could've gone either way but no point wetting ourselves over it now I suppose.
P.S. echo what others have said re Tod Jr. Need to get him tied up because I can certainly imagine there'll be interest if he performs like that in the league.