One revolution of the balancer is most definitely one revolution of the engine.
The amount of error you have is not of concern, just turn the relative cam sprockets, crank shaft back to where they should be..... Not sure why they have moved in that direction from undoing the nut though.
What you need to do is not spin the engine in such a way the pistons hit the valves.2 revolutions for one engine cylce, the cams spin at half speed etc. Maybe just read a bit more about a 4 stroke cycle to be more confident with what is happening