I guess my strategy will now be to stop at the direction of the LP guy but refuse to leave the exitway and demand that the police be called right then and there. No way would I give them a chance to "make the case" by planting something on me. Parents should be real careful that their child hadn't picked up any merchandise unbeknownst to them.
PS I am not a lawyer not did I sleep at a Holiday Inn last night.
Let's not underestimate the possibility that one of the minimum-wage cart jockeys will simply make something up as a reason to hassle you. Anyway, if you feel like being difficult, it's your prerogative ;)