One possible theory :
If HufflePuff is Stunna, it is more easy to understand all the story ... isn't it ? He play with bitcoin and if he has lost (he will not lose anything, because the btc is "yours").
I don't think someone know the cold address of primedice, so we have not any possible and valid information. Ours are only possible theory, finally I want to ask if I may : why isn't it possible to invest on primedice?
Well, if the reality is what you just said, I would like to ask you a few questions:
1) Why did Stunna do this?
2) What would stunna get out of this if he did it?
3) Considering Stunna's trust, will he really risk his trust to do this?
Also, it's all Stunna's personal choice. He might have thought it would be simpler if there's just 3 or 4 people investing.