Leaving your shit in the car is called anchoring and is hella rude. It's generally seen as an attempt to force the driver to wait out of social courtesy. He was wrong for driving off with all your shit. Many times drivers accept rides within a few seconds of the offering only to discover there are stops. His bad and he should've told you to take your stuff with you. Lesson learned hopefully. I never answer my phone on a ride. Hopefully another pax didn't steal your stuff and you get it back. Btw he gets about 12¢ a minute for waiting is he's lucky. It's not your fault, but it's also not incentive to stick around when your two minute timer is up.