But there was still time for giant Austria striker Maierhofer to be dismissed for a second yellow card, having initially been booked by Warwickshire referee Stuart Attwell for a foul on Tim Cahill minutes before Everton drew level.
McCarthy believed that Howard could easily have been red-carded too but declined to be drawn into a discussion about Attwell or whether the young official - who has been involved in several controversial incidents over the last two seasons - was intimidated by the crowd.
McCarthy did say: "The red card was harsh, bordering on downright disgraceful to be honest. I felt the first tackle he put in (on Cahill) was a booking for the manner he went into the tackle. But this is an intimidating place. (Everton manager) David Moyes is almost playing wide left for them, getting the ball back on as quickly as he can, but I've no problem with that.
"It all creates atmosphere and the crowd are loving it. But for the first incident, Stefan was just booked for his reaction.
"But for the second yellow card he did what I would expect any centre-forward in the world to do and that is to run across the keeper's path to stop him clearing quickly, that is all he has done."
He added: "But their 'keeper Tim Howard is very fortunate not to be walking off the pitch too. My understanding is that when you raise your hands above neck high and use your hands to push someone either in the face or close to it, then that is a sending-off.
"I feel that pushing someone in the back of the head - the back of the head is just above the neck as far as I am concerned - is close to getting a red.
"I felt it was unnecessary, he could just have let it go and everyone gets on with things. But it happens, it has taken the gloss off a very good away performance."