Ralls received a straight red card for a cynical foul on Lucas Moura, as Cardiff were beaten 1-0 by Tottenham at Wembley.
Neil Warnock was unimpressed by the reaction of many Tottenham players in surrounding the referee, which he feels contributed to Dean brandishing a red.
Pundit Kamara believed the decision was right, although conceded that the current laws of the game leave too much to interpretation.
"The way Mike Dean can clear himself is by saying this is serious foul play.
"Don't get me wrong, I agree that this should be a sending off but the law is inadequate at the moment. There should never be an intention to foul a player.
"If you bring someone deliberately down, I think that should be a red card anyway. What Joe Ralls does is exactly the same (as if he pulled him back)."