I had a 94 2.2L S10 and I bump started it all the time, it popped right off even in reverse (I replaced a couple starters). A couple times I'd turn the key back too far and it acted exactly as you describe. I've never tried to EOC anything with an antitheft device, but this seems plausible also. My Frontier and our Jeep only has antitheft on the doors and that's annoying enough.
__________________
|