ode Here is my reasoning-noting I didn't add this comment
4.1a(1)/2 – No Penalty for Stroke with Non-Conforming Club When Stroke Disregarded
If a player makes a stroke with a non-conforming club, the player is not disqualified if the stroke does not count in the player’s score.
Once he signed his scorecard, the stroke counted. The Golf Channel article gives me the impression he knew he used the club but waited to ask for ruling post-round. Had it asked after he hit the shot, and not count it perhaps not a DQ.
One of these dumb things. If not prohibited then should be a foul. This is why I play by PGA rules (Paul Golf Assoc), as my golf buddy refers to my play. He is Italian and much is lost in translation I remind him.