Yes, this wasn't ignored. But you can't be blamed for a sharp surface being in the way of a theft - What if the burglar cut themselves on a steel burr ? Same deal, only this guarantees the cut.
If this situation happened, and the thieves said "I got cut on his radiator" the court would laugh. It is defensible.
99.999999% chance they will cut themselves and go home to nurse the wounds and never do anything to retaliate.
There was ONE court that decided in favor of the plaintiff in a criminal case because of this circumstance, and thus the precedent was set. This ruling has only happened maybe 3 times in history, and I'm willing to bet (Although not sure) that that ruling came from the 9th Circuit. In New York, if you show up at a police station "I cut myself stealing some foo's audi bling" they would lock them up, throw them out, or flat out beat the hell out of them.
NY is a tough town. My friend got caught by a cop stealing back his own car, and the cop helped him to track the theif down and after working him over for a few minutes, brought him downtown for booking. I was present for this (I waited outside). My friend was black,the cop was white - But they were New Yorkers so they were on the same side. (The kid stole my friend's Cutlass to use it as an unlicenced cab for the day, and my friend found the kid, in traffic, and pulled him from the window and beat the shit out of him on the street. The cop came and broke it up, the kid got away (for a minute))