[There was a long pause before Oak turned away from Agatha, letting out a heavy sigh]

...I don't know. I don't have all the answers, but I do know your way of thinking will only aggravate the problem.

[He faces the old woman once more. He's tired, so very tired. If what he says now couldn't get through to her... then nothing will]

You said you understand a Trainer's bond with their Pokemon. Then you should know their love is inseparable and can never be broken. As long as they have that, as long as they have each other... then humans and Pokemon can coexist.