So let me get this straight. This author of that reddit post complained that you, the B-EX.IO exchange, incorrectly processed his first withdrawal, and your response to that was to refuse to process his second withdrawal??? That is not ok to do. 

Maybe the author would apologize publicly if you withdraw his money to him, but why would he apologize if you are still holding his money? That's not how apologies work. Like every other poster here said you cannot make users do something by holding their own funds over their head. You are not "bowing to him" by withdrawing his money, you are completing your obligation as a legitimate business and you need to do it or nobody will trust you.