If by end result you mean abject failure. 
Actually, if installed the other way, I'd think the Bell might have turned on (rather than the Horn). That is, a Uni-directional TVS will clamp at 1-diode drop or, say, 1 Volt on each half-cycle. I believe this is what created the DC offset as seen by the engine - thereby triggering the Horn. Of course, this would generate massive current, heat, and rapid component failure.
So, yes, same end result but I was curious about the intermediate result. 
