Murray made Norton captain last year because the Cowboys were getting the rough end of the pineapple from the referees. Because of Bowman's position on the field he was often unable to reach the referee in time to query decisions.
Bowman has since said that it was a relief to be relieved of the captaincy, as it was starting to affect his personal game. He is still part of the 'Senior 6' players within the Cowboys, and is very well respected at the club. You can be a leader without being a captain.
The rumours that you hear about were started (we think) by a former Cowboys player who left the club this year and now plays for a Sydney team.