Why did I spin a main bearing?

Sounds reasonable to me. Only thing i could find a argument for would be if it was bound enough to stop the engine wouldn't it have sheared something in the process.....idk?

Hope he doesn't feel to bad about this, years ago i did a berrybush, rings and new bearing rebuild on a SBC and broke a piston ring about the same mileage as him. Took a chance and got about 3k miles out of it....oh well:)

I can see that also. If that metal shard was left over from machinng and trapped in oil pump I can see that also. Something went through the oil pump. I wished he had posted a picture of the pump housing.