oil puke.. no I didn't drink it

Dieseling is usually caused by the throttle being open too far at idle, along with hot combustion chambers. Timing has nothing to do directly with dieseling as the ignition is OFF when it happens. Tming's indirect contribution to dieseling is in its effect on engine temps: Retarded timing can make the engine run hotter and thus contribute to the tendency to diesel.

In the case of a PCV, if it malfunctions and hangs open at idle and allows too much draw at idle/high vacuum, then it can feed extra oil/air mixture into the intake (which will combust) and act like a more open throttle. I have to wonder if the PCV is hung wide open, and allowed a backfire as part of the dieseling back into the crankcase that puked the oil an dipstick out. (But this all assumes you HAVE a PCV valve! LOL)