Rovers boss McGhee and Bantams chief Parkinson were speaking after an injury-time melee involving players and staff from both teams marred Saturday's League Two clash at the Memorial Stadium.
The dust-up was prompted by a rash challenge from Rovers' Seanan Clucas right in front of the dug-outs, yet he somehow escaped punishment even though he has already been booked.
Referee David Phillips instead dismissed Bradford midfielder Nathan Doyle for retaliation and, after some delay, issued a second yellow to Brown after consulting a linesman and the fourth official.
Rovers boss Mark McGhee said: "If Wayne deserved to go it must have been for something he did in the melee, He isn't the biggest, so perhaps he punched someone in the kneecap!
"Seanan might easily have been punished for the tackle, but we will have to see what the ref says in his report. As things stand, Wayne will miss our next game."
Bradford boss Parkinson was equally mystified. "It was a bad challenge and what my lad has done to be sent off I'm not sure. You always get a reaction to that sort of tackle. I think it was a case of mistaken identity with the Rovers lad, so the ref seemed to get it all wrong."