If the seller is paying for "your" agent, is she really yours in the incentivized sense? eg. Zuckerberg's college buddy who fronted the money for early FB serv

If the seller is paying for "your" agent, is she really yours in the incentivized sense? eg. Zuckerberg's college buddy who fronted the money for early FB servers was sure that "his" attorneys had his back, right up until they stabbed him, because they were paid by Zuckerberg.