The bearing probably spun and doubled up under itself, temporarily closing up the clearance under half of the journal, and quieting the knock. Oil pressure maybe came back because the bearing is now blocking the oil hole in the crank, which will also block flow to some other bearings I think. I'm betting it will look pretty nasty when you unbolt that cap. I replaced a crank on one where the bearing was actually extruded out of the rod and journal like thin taffy, leaving a spiral coil kinda' like a ribbon, all nice and blue colored from the incredible heat of friction. I think you will be safe leaving it parked.