The idea of fuel bending a propeller blade would to me imply that the drone cannot survivie e.g. rain. This doesn't seem intuitive. However, jets making closer and closer passes while trying to foul the sensors with fuel dumps, culminating in one pass that is so close contact is made, seems more likely.

You say "bends a couple of propeller blades and not the rest of the drone" but there's no telling whether contact was made with the drone airframe. We don't get a look at the Russian airframe either (to look for impact marks). The MQ-9 vertical stabilizers are "taller" than the propeller blades. I wonder if the Russian craft struck those, and the propeller was damaged by jet exhaust as the Su-27 pulled away.