what life lessons emerge from the film Lantana?

We watch this story unfold, and as it does we see multiple betrayals happening between many different characters. Leon's partner lies for him to Sonja about his whereabouts. Protecting him from her finding out about his affair. Jane then invites Nick over for coffee and Paula, his wife is betrayed by this as she knows that Jane is having an affair with a married man and sees it as a betrayal of her trust and their friendship. And one of the worst betrayals in the film is that of John to Valerie. She calls multiple times for him to help her as her car has broken down on her drive and she's stranded. He is at home and chooses not to answer any of the calls even as he hears them on the answering machine. By not picking up the phone Valerie ends up dying in the Lantana bush because he didn't want to face the difficulty of connecting with his wife as they've grown apart severely since the loss of their daughter.