I had a bloke overtake me today (he was on a decent bike / all the gear etc) I am unfit, in a suit on a cheapo hybrid.
He sailed past, right up to the next junction and undertook a bus and stopped level with about 3/4 of the way to the front of the bus.
At that point the one way system is weird, but the bus wasn't indicating and could have gone straight on or right (no actual immediate left turn) but still, crazy riding.
Unfortunately he was off and running by the time I arrived at the junction.
I always wait behind the busses there as 50% go straight on with a left turn with a blind pinch point about 100 yards down the road. I hate those moments - you feel you want to cover your eyes in case something goes horribly wrong