I was in a /duel with a MP friend last night. I finally got sick of having to mouse target his pets and ran out of range to give him the points without having to worry about derezzing because he was DoT'ing me.
So a few minutes later he was in a /duel with a MA friend of ours and he died.
I got Solo PvP points from him.
Apparently the system noticed neither of us died, and that I had more damage on him than the MA did (because she rather quickly splattered him), so she got Duel points and I got Solo points.