Please explain how the water will destroy the injector, pump, and what the hell does the regulator have to do with it?
Hell yes the providor should and must take care of what happened. It did not destroy the above mentioned items.
ps the "regulator" is an electronic chip and computer program.
I have seen water intrusion into injectors cause pitting and uneven flows. On a small engine it could cause severe performance issues. Especially if it is a high pressure system.