I think it's pretty obvious he's trying to shame the ones that kept it.
And your point is certainly getting through. I just don't agree with it. I'm just saying that there's some of them that might not be in a position to be able to turn down $500 if it's offered to them by a friend. That doesn't mean they're bad people.
I think I'm leaning more towards this opinion, mainly because giving to charity should be a selfless act with humility and compassion at the root of the intention. This is just turning an act of kindness into some kind of judgment day scenario/ circus. As for it being some sort of game that he likens to BB... Bloody hell, the show is over and the controlling games continue?
If it was me, I would publicly say 'no thank you, I have already donated to the charity of my choice and I myself am not a charity case'. It's kind of humiliating, the whole way he's gone about it. Seems that, depending on the choice the HM's make, it's REALLY all about either making Tim look good or the HM's who keep the $$$ look bad. I'd decline to participate on principle.