Actually the BEST indicator is that:
a. There are four damage spots along the rim on this coin. One is bigger than the others and gets all the attention. VERY BIGGEST CLUE. Don't needle pinpoint focus on one tiny area of a coin and make assumptions without looking the WHOLE coin over for clues. You had at least three other clues that this was damage.
b. The damage is somewhat soft edged.
Cuds are always cut, sharp edged.
c. The area in question has a dark spot (shadow) along the edge of the coin. That shadow is caused by a pit. The pit was pushed into the coin, so the metal had to go somewhere.