To me you are desperately looking for reasons to hold that money back. If op proves ownership through signature, AML requires you to exactly nothing and you are legally entitled to release the funds.
Why we should "desperately" hold 35k euro when we have been in business since 2011 and processed thousands of bank transactions ? No, we are just looking to find a solution which is legal and, at the same, time guarantee customer funds..... because Rock Trading are selective scamming this user.
Why did you name your customer without asking for consent before doing so?
So do you think all the people that say Rock Trading are scammers, are mercenaries?