It is clear to me that you should hold in camera meetings in which you are allowed to access certain information. However, you should understand that neither we in the social sciences nor anyone else is really able to tell you what the actual situation is. If you invite a firefighter to your place and ask him whether there are any fire risks in your home, he will find some. The same will be true of a security professional: he will always find threats.
I think your work requires that you find the necessary balance and qualified views on this matter. If you only speak to security professionals in a closed or in camera context, you may get too dark a picture of the situation.