I will give an example which I think is relevant, but I have no idea how to explain it. If anyone seen or knows gas welding, acetylene and oxygen are mixed together and the flame is used to weld metals. What I've observed years ago that welders use the following technique to cut metal. The cutting starts with the mix of acetylene and oxygen, but once the area is red hot, the welder would shut off acetylene completely leaving only the flow of oxygen, and continue cutting. Despite the absence of the fuel, the metal gets white hot and the welder is able to produce pretty long cuts. It literally looks like bare metal is burning in oxygen. Essentially it would seem that at really high temperatures, oxygen would just eat anything away, and I strongly suspect that's what might be happening in the engine when an unburned oxygen is present.