If you were Rob, and you were away at sea, then allowed back, don’t you think your best supports would be your colleagues who understand the pressure of being at sea during parental loss, and then back with your family who share in your loss and the memories?
Whether he’s only just back, or has been at his parents house for a few days - I suspect that’s given him more space to grieve and process than he would have had with Sarah and the kids.
She’s an emotional leech, at least this way he has had a bit of time with his own thoughts.