The 2 BTC rate per day is too small to launder such amounts of money unless they used so many fake accounts which brings the question of, how were they able to trace that all the bitcoins the claim went through Binance?
What kind of hacker would move such amounts of BTC to a centralized exchange where they can easily seize it without thinking of mixing it?
There are a lot of tools to monitor the transfer of asset to and fro, TrackX is one of them and I have traced many transfer to centralized exchanges. If it was reported and Binance does not block the account from operation, they will be guilty I think, but I am not a lawyer. The only thing they have to do is evidence they own the said amount of BTC, the transfer sequence to Binance centralized exchange and the official report to Binance staff of such movement.