I did not have anytime to spend on the bike this weekend but I did drain the primary and was a bit surprised. I probably added half a quart of oil just recently because I thought I had a leak that as draining it. I don't think I did have one though, as 1.5 quarts of oil came out of the primary. So like you suggested, Blltrdr, I don't think the primary case itself was leaking. Really had me scratching my head as I was "certain" it was so I'll have to see if it's the other sources you mentioned.
However, why would I get oil all over the back of my bike from overfilling the primary? Too much pressure forced it out elsewhere?