While details of the fine were not announced, the league and the National Hockey League Players Association have an agreement in place where clubs are not permitted to have club coaching or hockey operations personnel participate in any on-ice session with players during their off season.
Professional hockey is a grind and off seasons are designed in way that allow for players to police themselves, while taking time away from the daily grind of their season. Having your club officials oversee your time away from them is counterproductive and in essence could cause divisiveness for any players that were subjected to any specific occurrence relating to this matter.