I'm curious if technology is there to investigate and invest that would create a 3D box map around the pitch to say 7-8 feet high, or maybe crossbar height. Then something that allows the ball to transmit to the 3D box map and perhaps a chip/something on the player somewhere, per say the shirt or shorts that would allow for video to capture a player's silhouette to then see where feet, legs, heads, etc. are placed on such tight calls.
Perhaps roving/stationed cameras on each side of the pitch box that tracks along with the play so that any given moment a sideline 3D view is available.
And add a second on-field ref so that one is always with/in front of play and the other is behind play. Adding an additional official cleaned up the NHL imo.