Sven-Goran Eriksson and Chris Hughton largely agreed replacement referee Kevin Wright got the key decisions correct as Birmingham claimed a 2-0 midlands derby victory over Leicester.
Fourth official Wright was immediately thrown into the limelight at St Andrew's having been introduced at half-time to replace the injured Graham Salisbury, who sustained a calf problem.
Afterwards, Leicester boss Eriksson said: "The penalty I really don't know, I've seen it five or six times and I don't know if it's a penalty or not. I don't know if he touched the ball first. Difficult for a referee. The red card, he got it right. You're not allowed to tackle like that."
There were just over three second-half minutes gone when Jean Beausejour was sent tumbling in the area by Andy King, with Wright pointing to the spot and allowing Marlon King to slot home the opener.
Just six minutes later and Wright was again at the centre of proceedings, as he brandished a straight red card to Leicester captain Matt Mills for a two-footed lunge on Morgaro Gomis, with the decision coming much to the dismay of the visiting players.
Hughton was certainly stronger in his opinions on the penalty, while sharing the same verdict over Mills' dismissal.
"There was certainly contact (for the penalty)," he said. "Jean is a strong personality and if he thinks there's an opportunity to go through and score he's not one who likes to go down too easily.
"I presume if there's contact, and it's in the box, then it's the right decision.
"(Regarding the red card) both feet are definitely off the ground when the challenge is made.
"Everyone will look at it over the next couple of days and have an opinion. But both feet are off the ground and generally these days if that happens then it is a red card."