Last winter, I came home from a trip and was carrying a big duffel bag down the street. A guy walking the other way bumped into me and dropped a plastic bag, shattering something inside. It looked like a bottle of liquor and he said he just bought it. We argued for a second and he wanted me to go buy him another $40 bottle. I was exhausted from traveling all day so I just gave him $20 and walked away.
This morning, I was crossing the street and a guy bumped into me and dropped a bag and glass shattered inside. I looked back and waved sorry and kept walking. He yelled, so I turned back and realized it was the same mf! I laughed and argued with him before finally telling him to GTFO.
I googled his schtick to see if it's a common thing and realized it must be a version of a scam called Pèngcí. I'm kind of impressed because it takes some skill to pull off the actual bump, but navigating the argument afterwards also requires a delicate balance of outrage and "hey man, let's make peace" convincing and negotiation. Scammers are dedicated to the craft.
So since I've lived out a version of "fool me once...," now you all know what the deal is when someone bumps into you and you're 85% sure it wasn't your fault. It's probably an artist at work.