I've moved the steering around a bunch of times with the key off and never had a leak. Internally the power steering rack is a double end double acting cylinder. So all the fluid that goes out of one chamber is made up for by fluid going into the other chamber. It should have near zero net fluid volume change in the pump reservoir as you move through the steering range. That's true either on or off.

It's possible there's some random luck involved and the power steering pump stopped in just the right position that fluid wouldn't flow easily past the pump mechanism and it ended up pushing the fluid out of one side of the steering rack and pulled air down into the other and then it overfilled the pump and pushed some out. I can imagine that being at least possible. I've never heard of it and I'm not an expert on power steering pump internals. But it seem plausible at least.

I'd start it and cycle the steering back and forth a few times and check the fluid. Add some if it's low. And drive it and see if anything else happens.

good luck