Gatland said he had thought about asking a prop to fake an injury which, with his team already a man down after the sending off of captain Sam Waburton, would have led to uncontested scrums.
“After we had already lost (prop) Adam Jones (to injury) we discussed, ‘do we fake an injury to one of our props to go to uncontested scrums?’,” Gatland said.
“Morally, I decided that was not the right thing to do. I could easily have done that, but in the spirit of the game I didn’t think that was the fairest or right thing to do.”
However, any side trying to fake an injury runs the risk of being found out by International Rugby Board sideline officials whose job is it to check players are going off for genuine medical reasons.
Openside flanker Warburton saw red in the 19th minute at Eden Park on Saturday after Irish referee Alain Rolland sent him off for a dangerous “tip tackle” on Vincent Clerc that ended with the France wing landing head first.
Gatland again voiced his displeasure at Rolland’s ruling, saying: “I believe Alain Rolland made the wrong decision.
“I think the right decision was a yellow card.
“In terms of the rules, he is entitled to give a red card but every game is different,” the New Zealander added.
Wales, despite being a man down for more than an hour, scored the only try of the match through scrum-half Mike Phillips.
But France just did enough to win 9-8 and will now face hosts New Zealand in Sunday’s final at Eden Park.
Meanwhile Wales play Australia, beaten 20-6 by the All Blacks in the second semi-final, at Eden Park in Friday’s third place playoff.