It's a penalty, but my oh my, that is a harsh, harsh penalty, for what happened.
I look forward to the day when TV is not used in being able to call penalties, unless there is clearly intentional cheating.....and there should be a statute of limitations on being able to call a penalty....no matter how the info comes to light.
I love golf, but incidents like this put a black mark on the game. It really is a penalize because we can, not because it it is equitable to do so. It just rubs me the wrong way.