What is the most fucked up thing you've unintentionally done?

A few years ago, I was driving with a friend, and I saw a homeless guy on the side of the road, asking for money. I, feeling generous, decided to give him ten dollars. I put my hand out the window, waving the ten-dollar bill to get his attention. Just as I did this, the light turned green. My friend wasn't paying much attention, so as the light turned green (and as the homeless man was running towards me to get the money) he accelerated. This resulted in a homeless man trying to chase us down, and me (looking as if I was teasing him with money) laughing and crying at the ridiculousness of his expression. I felt horrible afterwards thinking about his face when he realized he wasn't getting the money.

Tldr; accidentally teased a homeless man with a ten-dollar bill

So, Reddit, what's the most fucked up thing you've done without meaning to?