'Gers powered back to the top of the SPL table with a 4-0 victory at Tannadice Park but it was the nature of the win which set tongues wagging in Scotland.
Referee Collum had three Dundee players sent off for challenges in the box, awarding Rangers a trio of penalties, and although the decisions were criticised by Arabs boss Peter Houston, Smith believed they were correct.
"If we look at the penalties, I don't think anybody could argue that each was a penalty," he said.
"Under the letter of the law at the present moment, the referee has no other option but to send the players off.
"It happens and it obviously dictated the manner in which the game was going to be played, especially after the second ordering-off.
"Overall, it was a strange set of circumstances in the game and, I stress, I think the referee was perfectly correct. I don't think he had any other option."