Sorry to disappoint you mate but Stake.com? if this is true then that Person have already file a case against stake in legal manner because 12 bitcoin is more than 600 thousand dollars and that is a huge amount for the person to fight for His right and you don't have to run after stake , because this become a thread of bitterness since you first put a thread against the sister company of stake and now in them directly.
Obviously the accusations are all fake, it's all hearsay you mean the guy let you in in his account, that could be a violation of the rule, only a player can log in to his account, especially if you are not on the same location, and with $600k on his account he can file or negotiate with a good lawyer to file a case, any lawyer will grab the opportunity to represent the guy, if he is not cheating and really deserves that amount.