again, what does these terps under these company have to do with two parties? The answer is very simple... RELAY the conversation PERIOD. Why do these relay companies need to be drawn into between two parties? Do you have any clue what would happen if these relay companies gets drawn into legal battle with two parties? You don't want see their price tag (Cost of defense), trust me on that one. If that happens, its very easy for any relay companies going bankruptcy.
Thats why FCC made it so simple and clear, the job of VRS terp is to relay the message, nothing else.