rulie
Head Pro
"Go ahead and mark it" is an acceptable response to the player. You haven't refused, just deflected! He might get the point sooner or later.The player is the sole judge, the rule is not qualified. If he wants your ball marked, you need to mark - that is precisely what the rule says. It could be worse, the player could also ask that any ball-marker be removed from his sight. But as rulie notes, the player can mark your ball himself in stroke play - which could be sensible if that avoids undue delay.