It’s not interference. Here’s the applicable rule.
Rule 48 – Illegal Check to the Head
48.1 Illegal Check to the Head – A hit resulting in contact with an opponent’s head where the head was the main point of contact and such contact to the head was avoidable is not permitted.
In determining whether contact with an opponent's head was avoidable, the circumstances of the hit including the following shall be considered:
(i) Whether the player attempted to hit squarely through the opponent’s body and the head was not "picked" as a result of poor timing, poor angle of approach, or unnecessary extension of the body upward or outward.
(ii) Whether the opponent put himself in a vulnerable position by assuming a posture that made head contact on an otherwise full body check unavoidable.
(iii) Whether the opponent materially changed the position of his body or head immediately prior to or simultaneously with the hit in a way that significantly contributed to the head contact.
48.2 Minor Penalty – For violation of this rule, a minor penalty shall be assessed.
48.3 Major Penalty – There is no provision for a major penalty for this rule.
48.4 Game Misconduct Penalty – There is no provision for a game
misconduct for this rule.
48.5 Match Penalty – The Referee, at his discretion, may assess a match penalty if, in his judgment, the player attempted to or deliberately injured his opponent with an illegal check to the head.
If deemed appropriate, supplementary discipline can be applied by the Commissioner at his discretion.