Is Sitter's Boyfriend Covered by Insurance?

We met a sitter for our dog and liked her a lot. Before leaving on our trip, she informed us that her boyfriend might be spending some time at our home as well, and asked if we would like to meet him as well. We liked him as well, and saw no problem wth his visiting. We have home security cameras, and the sitter and boyfriend were apprised of this fact. From the cameras, we saw that the boyfriend actually stayed here the entire time, and did 99% of the dog cares while we were away. While we are happy that SOMEONE was taking our dog out for walks and playing with him, we are concerned about the ramifications if something were to go wrong (injury to dog or person, etc) with a non-Rover person performing the cares.