My grandpa would have said "I told you so", now that I am the grandpa, my favorite is "It appears to be operator error".
......or "sounds like cockpit trouble."
Every year, those beggars would build their mud nests on the cooling fins and fan blade of my A/C unit. One mud house would always seem to bridge the fan to the housing, thus rendering the unit inoperable. Then, after knocking loose all the mud, the unit would run but the fan was now out of balance because on the remaining clumps. So I would have to pour water all over the unit to dissolve away the last vestiges of the dirt. Often, I'd have to repeat the whole process several times each year. I've even had them gum up the scatter plate on more than one feeder.
The suckers never seem to get tired!