Having a chaperone for guests just makes sense. At the very least, you can keep them from accidentally breaking something. If you're not escorting guests, you're doing it wrong.
Agreed. I have never seen any commercial scientific lab (bio or otherwise) that let anyone just roam free. It would be a serious liability to let people roam without a chaperone. That has as much to do with biohazard/radiation/toxic/laser signs plastered around as it does company secrets. That said, the chaperone in this case should be very accommodating to the visitor in terms of seeing systems and operations of interest.
