Guess I'm getting some J / K confusion here then - I'm fairly certain that the same doesn't apply to the K, as I have on more than one occasion had no roller on board when I could really have done with it.
Never ever saw the "front-enders" helping with a re-role in my time
Really? You need to kick your front-ender's arses then - I've helped out with plenty of re-roles and they're a major ball-ache. It takes at least 30 mins to go from full side & centre seats to full roller, with EVERYBODY mucking in - but again, this might only be applicable to the K.