The broken ring would cause more blow-by which can make oil push up the dip stick tube, and leak by other seals as well. If the crankcase ventilation system isn't working correctly, is overwhelmed with blow-by, that would make it worse too. The fuel in the oil probably raised the oil level which also added to the problem. I suspect fuel leak down past the rings was where the gas in oil came from. Residual fuel pressure in the system after shut down and leaky injectors can cause that.