I'm not saying abuse took place, just that the grandparents not calling the hospital isn't really indicating anything, and the passing off scenario is relatively common. It doesn't even have to be abuse, it could be stuff like an accident and the grandparents passed the kid off to the father because they panicked or felt ashamed if they admitted it kor cognitive dissonance that it couldnt be that bad). Again, not that that necessarily happened, but just that it's not an unusual scenario.