Never noticed, but it will be interesting to see if they reappear...
Aureolin hit the nail on the head when he mentioned about it being heavy handed to suspend the controller and driver.
How culpable are they? A wheel is obviously loose, there has been an obvious breakdown in communication somewhere down the line - but to repeat myself, why was the wheel loose in the first place?
Whether it was a fitter not doing their job properly, the other driver for not reporting back in sufficient detail, the controller for not being clear, the driver for not checking fully - who knows. But by removing that visual aid, GNE have hamstrung the driver as to what he can actually determine whilst in charge of a bus full of passengers parked on a busy road.
Not sure whether GNE would issue drivers with a wrench, but I would imagine the fitters use a pnuematic power wrench. As you say, there is only so much a driver can do.
RE: Go North East