One of my old habits with air compressors is to pull the ring so the tank blows itself out when done. This comes from the expensive Iwata compressors that are used in airbrush makeup work. Very precise machinery, but they do need to have the tanks emptied after a work session so there is no chance of water getting in the tank (there are water traps, but even then, any water going out the end severely screws up an airbrush job.)
I can easily see that happening though. It can be easy to position an air compressor near a generator's exhaust.
