Crankshaft Rotation

I am replacing all the components of my magneto. I had a VERY difficult time getting the flywheel AND the flywheel nut off. My manual cautions about not rotating the crankshaft counter-clockwise. Could someone tell me why? With all the effort of getting the flywheel off, I certainly turned it in the wrong direction at one point or another. If the concern is the magneto components, I'm replacing them anyway. If its something else I wonder if I should check on something?
1965 33HP Evinrude Ski Twin

Thanks! Joe

Not sure about why not to turn the crankshaft on your motor counter-clockwise but I will tell you that the nut holding the flywheel on is much easier to get off with an impact wrench. I have had issues with the nuts before and they just seem to fall off with an impact wrench.

The general reasoning behind not turning the crank backwards is that you keep the blades of the impeller from doubling back on themselves and possibly staying that way.
A good fresh impeller will usually re-orient itself. If you are not sure then adhere to that practice.