That specific staff member's access to the staff section was removed by Yop all together because he/she was leaking information.
Actually, this... isn't even close to the full story. There was a long history of events, including repeated flaming and trolling, that lead up to this person's removal from staff, and it is entirely likely that they would have been removed from staff
even if no one had leaked anything. Indeed, Yop, X, and Mako were already seriously talking about doing this before the leak was even revealed, and as soon as we found out there was a leak on staff, suspicions naturally fell on that person instantly precisely because of these events. The leak was the final straw that removed all doubt that this person would be removed from staff, but they probably would have been removed regardless.
As for the claims in the OP: Complete bullshit, of course.