I say it's worth a try and see if that resolves the issue with the second plan of action is just buying the latch as noted.

 

Just had the same thing happen some weeks ago. Unforced error as they say. Have a door latch laying around but not looking forward to removing the interior door panel again. Anyone else have more info on this symptom??

(window goes down when I grab inner or outer door handle, however when I release the handle the window goes up again even if the door is open).

 

100% positive on the latch fix, had it done to mine also, found a used latch on ebay for $50