I had a mate who worked in a sevice station. On several occasions, he did this when a customer pissed him off, usually with the customers car on the hoist, and the open container of fuel close by. ( The fuel was used to clean parts, this was quite a few years ago and in a somewhat backward country garage ).

^ He said 'mate'

tee hee

I used to work with a crack head harley mechanic that would do that, scared the shit out of me the first time he stuck a cup of gas in my face and threw a butt in it...he also soaked his dentures in gas to clean them.