Why: because it is impossible for a third party to be 100% sure it is CH's account.
I agree with you on everything. I think those people had no right to claim for any action after acting so stupidly.
But CFB may know the account. When he settled previous trades, and asked CFB to move funds, he had to sign his BTC address that participated in the ICO or provide his iota seed, to confirm where to move funds from.