I believe that the converse of, “Are you comfortable asking a dumb question in public?” is, “Are there precisely structured communication flags set in place for assigned tasks and procedures in the case that assignees are not familiar with the environment.”
If you’re managing a remote worker, or working with other remote team mates, one protocol for dealing with unknowns could be Slack / chat, where anyone could feel free to interrupt anyone else at any time or at set intervals. However another protocol could be a list of assigned activities - perhaps a Trello or GSheets, with tasks and assignees, and a way to, “flag” any particular item for review for what unknowns may come up.
Unknowns are inevitable. We all engage in knowledge work, and it is incumbent upon the managing party as well as the working party to be able to come up with a system that manages the flow of that knowledge.
I use this type of system myself because not everyone can be available at all times for every given question on Slack, and then questions get missed…so there needs to be a way to flag and clear flags, and remote workers need to be able to clearly understand that they absolutely can feel free and open to say, “I don’t know,” or “Can you confirm this?”