[Clembo]

Legally, I believe they have to patch a radial tire with a patch from the inside, requiring the tire be removed from the car and unmounted from the rim. Probably didn't want to be bothered doing the labor or charging you what it would have cost. Mom & Pop places often use a plug and goop from the outside while the tire is still mounted and on the car. I've had both done and never noticed much difference. I wouldn't recommend using a patched / plugged tire at the track however.