Would this cause the rear camber to be out of spec?

most common cause is when someone jacks the car up on the rear beam bending it and changing camber angle

as for ushes not 100% sure

The rear beam is a pretty solid beast.... I am surprised that jacking on it will bend it so easily. That said mine does BadThings to my rear tyres. I was going to change my bushes this weekend but the useless to$$pots at Loders Skoda never got the bushes in for me (even though they had the best part of a weeks notice), or if they got them in, then never phoned me to tell me.

its not that solid when you jack a 1ton plus car up on it lol it just bends

its not that solid when you jack a 1ton plus car up on it lol it just bends

Fair point....