because the money was held in bitcoin, not fiat, and then he claimed the wallet was hacked. for all we know, the wallet really was hacked.
however, this is my take on it. it seems like shakoor didn't really understand how bitcoin works. he refused to give up the password to the known scam wallet, which suggests the coins were still there and not really "hacked". his associates probably just looked up some of the wallet addresses and realized the coins were never moved.
now that he's dead and the rest of the gang can't access the wallet, 6000+ BTC are probably now lost and removed from circulation.