I got violently thrown out of a house party in Xalapa, Mexico by an enraged drug dealer after I pointed out that he had shorted me on the weed. I was supposed to pay 250 pesos ($12) for 4 grams, but he only bagged up a gram and a half. A very common practice with drug dealers selling to tourists in Latin America. Respecting the owners of the house, both of us were completely silent during the altercation.
It all started off very well, with the owners treating me like an honored guest and feeding me dinner and beer. Unfortunately I had forgotten to bring water, and after smoking, I suddenly began feeling extremely dehydrated from the salty dinner. When I asked for water, they mocked me and said "we don't drink water, we only drink beer". Then I said I was going to drink out of the tap. Horrified, they then poured me a glass of water. I simply ignored the rising tension in the group, led by the drug dealer who showed up with a huge boa constrictor over his shoulders, accompanied by several young girls. He hated my gringo ass from the moment he saw me.
After I got back in my truck and drove past the police substation right next door, a police truck came up behind me with the lights flashing. I kept driving, a little drunk and a little high and a little shaky from the adrenaline dump. He did not blip his siren, and I turned onto the dark narrow street near my hostel with a huge sigh of relief.
Another time I tried to buy weed in Tuxtepec, Oaxaca...but ended up with some drunk guys trying to grab my wallet out of my pocket. I told them "creo que es robar" and power-walked away from them. One advantage of being tall is that short shit men have to run to catch up with you when you're walking at full speed. The police also mysteriously pulled up a few minutes later as I was trying to find my way back to my hotel, a lot drunker than I realized. They decided not to fuck with me and drove off.