Les Gones were enraged by the decision to award a penalty against Mouhamadou Dabo for handling Marco Estrada's free-kick, but their coach believes that anger inspired them
Les Gones were twice forced to come from behind during the game in New Jersey, with Bafetimbi Gomis and Jimmy Briand cancelling out John Utaka's stunning opener and a penalty from Emanuel Herrera respectively, before clinching victory courtesy of a 4-2 shoot-out success.
Garde felt that referee Jorge Gonzalez's decision to penalise Mouhamadou Dabo for handling a free-kick from Marco Estrada struck had been the decisive moment in the game.
"I think there were several elements to explain the differences [in Lyon's performance level] between the two halves," the former Arsenal man mused during his post-match press conference on Saturday night.
"The first half was a case of there being some emotion and I think we didn't play in a liberated fashion. I asked my players at half-time to play with more freedom and to try to attack.
"The second half started with an injustice, with the referee giving Montpellier a penalty which I don't feel should have been [given]. But that stimulated my players and got them playing together more and going forward together.
"I also think there was a physical aspect and we finished the game more strongly than Montpellier."
Garde, who was capped seven times by France, took charge of Lyon last summer, succeeding Claude Puel as coach.