[Christ]

Too much oil doesn't prevent the cylinders from moving at all... it just makes it alot harder. While oil doesn't compress, it does move. As one piston is coming down, another is going up, so the fluid is getting forced elsewhere in the crank case. The last thing that would happen from that is a seized piston. More likely what happened was that the flickering oil light was from a failing pump, and intermittent pressure, but without seeing the engine first hand, my guess is as good as the stuff in the cat box.