[steely]

I knew an indy shop owner and was aware of a customers vw wheel being damaged by the machine that was used. The shop owner brought it to the car owners attention and made things right.

You could always leave the guy a message if you're concerned about the time thing.
Then call him back or show up with the tire. He might even recognize the pattern and age of the damage. You'll know how much character he has right away.

He won't be happy, but it's not like it was your fault.
As for how much he goes in for the repair may be a different matter.

Good luck