I don't think he would win that, since he obviously misused the urinal intentionally. You can't sue a gun store because you shot yourself in the foot with the gun
get a good lawyer and you can say "the urinal did not meet safety standards, as i turned around to look at someone entering the room, the urinal fell and a shard went into my asshole."
my school removed urinals from all toilets because some genius tried to sit on one like a chair and broke it and got his asshole split wider with a broken piece