Update. Still a mystery
Our best guess is that is only happens under load and above 4500 RPM (highway driving). This implies that the leak only happens at higher oil pressure and would spray. Maybe the oil filter is compromised somehow (it was not lose or visibly damaged). Any solutions to this puzzle would be much appreciated.
1. Leak in front was coolant. There is not oil in the coolant.
2. Back skid plat is dry except for a little coolant blown back
3. The engine is completely dry top, bottom, front, and back. The mechanic used a mirror to look into tight places.
4. The oil pan is pristine. It was replaced last year due to a crack and still looks brand new.
5. Staining on the rear axle beam and oil filter appears to be dried blood and fur
6. Above and underneath found no oil staining
7. No oil in emission/vacuum lines
8. No codes and OBD2 shows everything in normal range
8. With engine running at idle and at 3500 RPM (no load) there are no signs of oil loss
9. Next test (proof) is to top off the oil and drive at highway speeds for a quarter tank then check the oil level