The Rugby Park skipper was ordered off for a two-footed challenge on Nigel Hasselbaink while Shiels himself was sent to the stands for protesting against two further decisions.
Shiels said: "The young lad, the fourth official Andrew Dallas is quite inexperienced and he made the decision, Steve O'Reilly got in his ear, which was astonishing that the young lad was influenced like that.
"You could see from the naked eye that he got the ball, then I got sent off for contesting two decisions.
"I didn't use bad language and was quite clear in my head that I shouldn't be sent off.
"We deserved something out of the game, but switched off for the winning goal - it's so disappointing after being so dominant."