Water pump tends to leak a bit further back.
I believe your answer is in your first post. They swapped your lower hose, and it's right there on that side. The lower radiator connection point is right there at the bottom. You being a reasonable guy who tightened his own trans line (it's because they didn't have the right tool for the line and undid the fitting instead BTW) leak, therefore had the level sensor been leaking, I think you'd have said so. Likely there was a little corrosion on the outlet of the pump where the hose connects or at the radiator. Both will end up wetting the same area. Although the upper one might also drip straight down as well as running down the hose.
The fix.. Loosen the clamp and move the hose a little and or swap out the factory engineered clamp for a worm drive one. Aka..you add the worm drive next to the factory..cause you aren't pulling the clamps off.
