I don't know the situation you described, but this is the rule:

Rule 6/13
     o. When a stoppage of play in an end zone takes place and is
        followed by an altercation (wheather a penalty i called or not),
        an attacking player on the ice or other player coming from the
        becnh shall not enter the end zone farther than the outer edge
        of the face-off circles nearest the blue line.

        PENALTY -- Face-off at the nearest neutral zone face-off spot.

Obviously this is a judgement call by the refs -- was it an "altercation"?
Where where the players before the whistle, etc.

        --david