[Shotimes] Oil in the gas tank

[av8r567@optonline.net]

My friends ex-husband said he poured a quart of oil into her gas tank.  Maybe he's just trying to scare her or maybe he really did do it.  How can we tell?  Will there be lots of smoke coming out of the tailpipe?  Will the engine run rough?  Will there be any damaging effects?  Will the oil ruin/clog the fuel injectors?  Will it foul the spark plugs?  Will it even get that far or will it get caught in the fuell filter and possibly clog that up?

If we do see evidence of the oil contamination (smoke from tailpipe, for instance) is it OK to continue to run the engine or should the tank be dropped to drain the gas/oil?