He wouldn't have just stormed off without securing that RV, having some local cops watch the lot so that it didn't leave. Have the local cops watch the lot so they didnt try to destroy evidence. That is a plot hole.
NOt a big one, but a plot hole nonetheless.
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Also, he had probable cause to search since the RV's owner told him that it had been stolen by her now deceased son. Even without a report being made, he could have made the case for a probable cause search of the vehicle on those grounds.
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Ok so the two Mexican brothers are trying to kill Hank in the parking lot... The one bro gets smashed between two cars, the other puts 3 or 4 bullets into hank, has hank dead to rights on the ground can just shoot him in the head.. but NOOOOOOOO, he decides to walk to his car to get his shiny axe.

slowly walks back (never mind there are probably a billion cops on the way) and takes his time standing over him, hank is lucky enough to find one bullet on the ground, loads it into his empyt gun, blows the guys brains out, and he drops the axe and it falls and wedges into the concrete. That was pretty stupid and very unbelievable. I consider this another plot hole. A real assassin just blows his brains out then and there and makes his escape.