The uoa's are probably on bitog as well posted by gathermewool. I don't think they sheared as much as the above uoa though.
Ok, I searched for you:
Of course, my comment about using a lighter oil was in jest (in case anyone is wondering) but check out the uptick in uoa wear metals. Your point about used oil contamination is a good one. That's why I take my samples from the dipstick tube using an oil pump. Then there is always the possibility of lab error.