Here's what to do...
First, pull them
Second, find a bike you like on CL
Third, stash tires in some bushes near target CL location
Fourth, test ride
Fifth, VERY QUICKLY, change tires, don't inflate. Stash other tires as minimum return
Sixth, apply fake blood
Seventh, go back to seller, say the tires both gave, point to the sidewalls
Eighth, demand bike for free
Ninth, pick up stashed free tires