The 59-year-old coach was in charge of La Paillade for four years and led them to the Ligue 1 title in 2011-12, but left the club in the summer that caused a rift between him and Nicollin.
"I'll just see what happens, but I am a polite and well brought-up person," Ligue1.com quotes Girard as saying.
"I regret the fact that we could easily have parted on better terms. But we had arrived at the end of a cycle and it was time to go."
Lille are currently third in Ligue 1, while Montpellier are eighth.