My experience has shown that 99.9999% of individuals who use a stall, bring their case/briefcase/carryon bag, etc. into it, rather than have it out of sight, vulnerable to a thief walking off with it, while you're sitting on the can, with your pants down around your ankles!
I always do. I prop the laptop up against the wall or door and use my carry-on bag to prevent the laptop from rolling onto the pissy floor. There's no way I'm leaving my laptop and carry-on unattended and outside the stall.
Well, that and it’s the LAW to do so in airports — they ask you if you kept your bag in clear view at all times.
And, to continue the thought, the ONLY place you can fit your rolling luggage in the stall is at the door. Plus, you want to keep everything you own as far away from the toilet as possible, because a lot of people mess up the floor around the toilet.
In fact, some people take wide stances in toilets to help hold their pants up so they don’t touch the floor, because of the filth on the floor around the toilet.
And to continue — since at the time, Craig as alone in his stall, and the undercover cop alone in the OTHER stall, what “conduct” would Craig be blocking with his bag?
Wouldn’t the “bag blocking the door” make more sense after the two men were in the stall together?