Right, and the key phrase there is "she didn't own the character."
Which suggests she was emotionally shaken by that. If she weren't, why make a statement one way or the other? VP's statement about Pam had always been "Pam died in the car crash." That suggests she was done with it. She'd moved on, but apparently she hadn't. They never said Victoria Principal is returning, or might be be returning. They had a storyline where Pam, a character she didn't own, might be returning. So I guess she figured: "You didn't ask me back so I'm gonna screw with your storyline. I'm not gonna be playing Pam and I don't want anyone else playing her either."
Bobby's attitude towards people was "what you give me is what I give you back." Pam abandoned him and their son. She didn't even give him the courtesy of a phone call after her vocal chords had healed. She insulted Bobby by sending the message that he couldn't possibly love her anymore since she wasn't still pretty. Bobby must have thought: "After all these years, you think my love is that shallow"? He responded in kind. He gave her back what she was giving him.
When Bobby's wife April died, she loved him and wanted to be with him right to the end. Naturally, he had a very emotional reaction to her death. So Bobby dedicated abut a half year of his life to doing nothing but tracking down the woman responsible for April being killed. The only thing that stopped him from following through on revenge was he learned that the woman responsible had a daughter. That daughter was adopted, as she was an orphan. She would have been completely alone in the world with no parents except for that woman - the same woman who was responsible for April's death. Bobby showed her mercy for just that reason. Not that she deserved to live, but her daughter didn't deserve to lose another parent.