if you read the highway code (think that's where i read it) the Emergency vehicles are trained, and will move around you, not the other way around, if you moved into the bus lane, instead of the ambulance ? the ambulance could have just gone around you rather you making a quick divert means the driver of the ambulance has to take evasive action
You'd think so... But i've had a police car right up my **** before flashing me to get out of the way with a completely clear bus lane to my left!