I don’t honestly believe they know any more than they are letting on. There were too many other adults around and they would not be able to keep their stories straight.
What they did was really stupid but they price they have paid for that stupidity is incredibly high.
From what I remember, there were some discrepancies between versions of events.
My natural instinct is to feel sorry for anyone who makes an error of judgement, no matter how huge, but I just think there's more to this than meets the eye. There's just so much stuff out there that paints them in a bad light, although I do realise that it's easy to be caught up in these things.