The conflict is in that even though he says Anakin is dead at the end of the fight and during ANH, him sparing Vader demonstrates that he can’t make the final steps to fully commit to that idea. It adds weight to him telling Luke that he must kill Vader by showing it wasn’t a decision that he took lightly. It also adds depth to the “certain point of view” thing by showing it as not only a lie that he used to manipulate Luke but also a lie that he’d been trying to convince himself of as well.