The bench should have gotten a minor for too many men 100%.
If you can find me an NHL rule where it justifies that penalty i will delete my account.
Rule 74 - Too Many Men on the Ice
74.1 Too Many Men on the Ice - Players may be changed at any time during the play from the players’ bench provided that the player or players leaving the ice shall be within five feet (5') of his players’ bench and out of the play before the change is made. Refer also to Rule 71 – Premature Substitution. At the discretion of the on-ice officials, should a substituting player come onto the ice before his teammate is within the five foot (5’) limit of the players’ bench (and therefore clearly causing his team to have too many players on the ice), then a bench minor penalty may be assessed.
When a player is retiring from the ice surface and is within the five foot (5’) limit of his players’ bench, and his substitute is on the ice, then the retiring player shall be considered off the ice for the purpose of Rule 70 – Leaving Bench.
If in the course of making a substitution, either the player entering the game or the player retiring from the ice surface plays the puck with his stick, skates or hands or who checks or makes any physical contact with an opposing player while either the player entering the game or the retiring player is actually on the ice, then the infraction of “too many men on the ice” will be called.
If in the course of a substitution either the player(s) entering the play or the player(s) retiring is struck by the puck accidentally, the play will not be stopped and no penalty will be called.
During the play, the player retiring from the ice must do so at the players’ bench and not through any other exit leading from the rink. This is not a legal player change and therefore when a violation occurs, a bench minor penalty shall be imposed.
A player coming onto the ice as a substitute player is considered on the ice once both of his skates are on the ice. If he plays the puck or interferes with an opponent while still on the players’ bench, he shall be penalized under Rule 56 – Interference.
