I have never had a problem withdrawing from BM/JB. It's my favorite book next to BOL. But I will say there were multiple reports recently of customers opening accounts and then getting them frozen. My friend opened one about 6 months ago and deposited $300 and then it got frozen. He ended up getting the money back after filing a BMR complaint (Thank you BMR!).
This could be a case of scamming or multi-accounting. But it could also be a case of BM connecting accounts through btc addresses that aren't really connected.
The amounts are troublesome. Most users don't have 25-125k in an offshore sportsbook. Also the fact that 2 of the 3 posters are female makes me raise my eyebrows. I've met one girl in my entire life that likes to gamble on sports like men do. It's very rare.