The other day my hedgehogs heater malfunctioned and the thermostat shut it off. It was so cold without it I put her in the snake room/office for the night as a temporary solution. When I moved her back out the next day he asked why and I said that I just didn't feel comfortable with her in there. I'm not sure if hedgehog smells like food or not like a rat would to be honest, and figured it would be best if they were not in the same room. Personal decision.
He made a comment about how that was stupid because it's been proven that keeping predator and prey on the same room hightens both animals activity and, "makes them more alive." I don't know the science behind that or if it's true or false but all I could think of was, yeah because one smells something delicious and wants to eat it and the other smells that something that wants to eat it and is terrified.
We had a nice long chat about how idiotic that was because all I could think about was him keeping a nice juicy rabbit in the same room as his anaconda because it, "made it more active and alive." I don't think any incidents following that would truly be called an accident. With enough photos of large snake bites cause by a food response, I think I got through to him... I think.