Presentation nightmares (British Airways Business Life) – "And another friend confessed to an incident when he tripped on entering the room where the clients were assembled, and spilt an entire – and extremely hot – latte down his shirt. In one swift action he yelped at the top of his voice and, in a bid to avoid being scalded, tore his shirt off. To stunned silence. Once the clients had assured themselves he was OK (presumably to avoid some sort of lawsuit) they said he could continue, and he had to give the entire presentation topless. They went with another company in the end"

[This reminds me of another wet T-shirt story that's very popular on BML. The article the above is from also includes a couple other short, but funny, presentation horror stories.]