You know, as well as myself and others, these types of UOAs using Pennzoil oils is not the norm. The OP clearly, imo, has something else going on or has forgotten about something.
Hadn't forgotten anything and no MMO ever went in the oil. I may have run a small amount in the fuel but that should be a non issue. When I do a UOA I try to keep it as controlled as possible with as few variables as possible during the OCI. Meaning same oil for top up (if any), no additives, etc.
This was just a "wonder how a UOA would turn out if I went to 10k?" Which I've never done before. If I had to guess, the high miles probably contributed to the lead -- perhaps bearing tolerances are out of spec or something. I have no means to check oil pressure, someday I might get a gauge and see what it is just for grins.
I'm happy that the oil held up as well as it did - I have no problems with the oil used.