(This is a series of reflections on Horstman’s Laws)
You could communicate more. Even if you feel you’ve already told them, even if you think they ought to know by now. It’s always, always, always better to risk over communication than risk under communication and all the risks that flow on from that.

Try this: ask yourself, “What if Person X actually hasn’t understood what I have been asking them/telling them? What might happen if they’re not thinking what I’m thinking?”

Yeah… That’s why you should just call and check, and communicate again.