No, the scratch was irrelevant at slowish speed, as the nine ball wasn't very close to the pocket. Being able to roll in a ball softly is a skill that every top player needs to have, but if they either don't have that ability or don't trust the table, it's the wrong shot. FWIW, Efren was the best I've ever seen at slow rolling balls into the pocket. My guess is that he'd have surprised you on many occasions, and the tighter the equipment, the more often you saw him slow roll it.
The chance of this shot rolling off is less of a mystery when a team is playing its third straight match on the same table. Hence, the chance of a roll-off is a risk that the shooter would have been well equipped to judge accurately.
So, I'm returning to the point that you have to trust the player's judgment here.