'One man's mistake is another man's opportunity'
These words pinched Oliver's heart but he couldn't say anything as it was the truth. Leaving Rachael's hand for whatever reason he had was his mistake, a big mistake.
Grabbing her hand and giving her the love and respect she deserved was Andrew's opportunity.
"I know you came back with a hope in your heart but you are never gonna get what you want," Andrew added. "Rachael is mine now. She doesn't need you anymore because she has me."
Though all the misunderstandings and insecurities he had were gone, he wasn't okay with Oliver lingering around Rachael. Not because he didn't trust her, but to make sure he doesn't cross the boundaries and do something impulsive.
Just because they were married and he knew Rachael had genuine feelings for him now, doesn't mean he would stop being protective. If he didn't protect what was his, who would do it for him?