Yes, and that experience was... becoming a junior coach in the Nashville Predators organization. This tells us that he weighed the benefits and costs of staying in Montreal and decided that taking a job in Milwaukee was a better idea. If he'd expressed any real desire to stay, you don't think Montreal would have been able to shuffle him down to their AHL affiliate for some head coaching experience?
Look, I want Muller to coach in Montreal - the narrative is perfect - but only after he's cut his teeth somewhere else. Despite the obvious negative impact his departure had on the team, it needed to happen since he's not ready to take on the top job with one of the NHL's flagship enterprises. Let him bumble and learn in Carolina, and return as your qualified saviour in 2/3 years.