As I came past Victoria Coach station from Elizabeth Street I could actually smell diesel. Turning into Bulleid Road (where the coaches also pick up) I had to swing wide to avoid some pedestrians and lost the back wheel on a slippery surface. Regained control with no problem.
It may be that a coach has been over filled or whatever and was spilling diesel, particularly as it turned the corner, hence the road being slippery on the outside of the corner.