If it fell on the right hand side then the oil pump would still be able to pick up and keep the crank fed, and for 3 seconds you will have no probles.
The light may stay on a bit as the pressure switch gets filled with oil and takes a few mins to empty out.
If it goes down and runs for a while you can have the crank running without pressure, but at tickover its unlikely to do any damage.
I crashed at cadwell a few years ago and it bent the throttle tube with it half open, so it was on its side at about 8000 rpm until a marshal could get to it and work out how to shut it off (about 2 mins) and that did **** the shells!
Its worth doing an oil change after your bike has been on its side, as the filter empties itself into the sump and you get a mix of very dirty oil
