I do solar O&M for commercial sites. We have lost 2 panels out of our nearly 20,000 to hail in 16 years of operation. Baseballs and birds dropping turtles have killed far more panels for us.
Largest killer is squirrel, those little monsters love the flavor of pv cable it seems.
It really is, hard part is sorting through the errors and figuring out just what in the world caused the error. The amount of hardware between the inverter and grid is impressive when you have a 100kw+ system. Over 250kw it gets even better because hydro needs to be able to remotely kill your power.