I'm confused. You said "everything was working just fine when I pulled into his house", but you said you found metal and c clips in the oil pan? Metal and c clips would indicate everything was not fine.
I'd be more worried about what that was from.
As for no oil pressue; bad pump, huge oil leak, or there's something wrong with the pick up. Since it was working when you pulled in, leak, or problem with the pick up would be my guess.