That’s very handy to know. I wouldn’t have understood it as working that way, but it’s quite clear why that would be, now that you’ve mentioned it.
As an aside, complicated if and/or statements seems to be a weak point of Inform. I haven’t noticed a way to conveniently give them an order-of-operation. I can’t think of a good example, but I’ve bumped into it a few times and had to take the long road home.