Simple… if you have a PIA, the person who you have the PIA with is now your client, thus you are liable to them. Granted, you have a liability to the homeowner, but on a different level than to your client. If you are inspecting a home, and the neighbor comes over and engages you in conversation regarding information about the home, let’s say the damaged that occurred in a storm three years ago, are you now liable to him? That would be ridiculus. No PIA, no inherant liabilty.
I think too many inspectors are too concerned about covering their arse, that they forget about taking care of their clients, and doing the right thing. This practice will be the destruction of this "alledged’ industry. I’m not saying to be stupid about it, just do what you (should) know is right!