Or, how about finding a live .22 long cartridge and repeatedly throwing it against the patio slab until something--I don't know what--goes zinging past your ear?
Nope... I don't know about that, either.
I do know a little about gyms and weights, though... and cartridges.
A .22 cartridge would tend to lie flat on the floor--those little guys don't really like to stand on the pointy end which would more fully expose their cute little primer rims. And any weight (dumbbell, barbell, or plate) falling on it or set down on it would almost have to cover a significant portion of said cartridge in order to provide enough force to fire the primer in the rim.
The physics involved would then suggest that the discharged cartridge would force the bullet along a path roughly parallel to the floor.
So, my question would be: What sort of exercise were you doing while lying on the floor that allowed you to drop a weight with enough force to discharge the .22 cartridge that would have to be within inches of your shoulder?
None of it computes.
On the other hand, if the dude involved doesn't care, why is ANY attention being paid to this by the polizia? Don't they have jay-walkers to write up or something?