Things that make you go "Huh?"

As I'll be driving up to Dallas Friday to visit the every lovely wrenlet, I figured it'd be a good idea to get the oil changed in the car. They scoped out my tires while they were at it, and told me the right front had a nail in it. (At which point the guy kind'a leaned in an mentioned the discount tire place down the street was cheaper.) However, the discount tire place couldn't find a nail or a leak! They even checked out the right left, in case of confusion, but nope.

So now I'm paranoid about which one's right, and armed with Fix-A-Flat just in case.