Will an officer usually charge a shop owner with possession in a CUSTOMER's vehicle?

I had taken my car to get painted and had accidentally left a bag of weed in it. The painter had called me and told me he didn’t have the money to spray my car because he was arrested for this bag of weed. The bag contained a little over a gram. It was dirt reggs by the way.

He claimed he was pulled over for my cracked taillight and the officer had searched the vehicle and found the weed. The problems with this story are:

1) A cracked taillight does not translate to the probable cause necessary to search the vehicle especially considering it was a customer’s vehicle. He claims he denied the right to search but they brought dogs. A denial of search does not constitute PROBABLE CAUSE (even more than reasonable suspicion). Even the fact that he has had priors does not constitute probable cause. He must have been drunk, high, or just a dick to that cop or did not assert his rights.

2) He had a receipt showing it was a customer vehicle. When the cop runs the plate it shows as a customer’s vehicle. I had a million pay stubs littered all over the floor with my name. I know “technically” he was in possession but would most cops be understanding of this.

I feel he is just yanking my chain and trying to get some more money out of me. If this is true however are there any ways I can help him WITHOUT taking a charge myself. Does he have a good chance of winning in court? Should I feel responsible or did he fail to assert his rights\was doing something wrong in the first place.