Kuznetsov didn't like Laviolette. Kuznetsov also used cocaine, so his mindset... may not have been right. I won't take anything away from Carberry, but the Capitals roster was remade with some solid veterans in the right roles and young players who are breaking out all at the right time. Doubt players like McMichael and Protas would have any complaints about Laviolette.
Maybe Laviolette wasn't the best coach for Kuznetsov, and isn't the best coach for Lafreniere, except Lafreniere was put with Panarin and Trocheck by Laviolette, and it's to that he owes the 52 million dollars he's going to make over the next 7 years.