I basically agree with you, but don't think you should worry about someone else coming and taking the laptop. It's the person you asked to watch it that knows y

I basically agree with you, but don't think you should worry about someone else coming and taking the laptop. It's the person you asked to watch it that knows you are gone, if anyone, it's they that would get up, take the laptop, and go. But I think that risk is fairly small if you pick the right person. Ideally someone else with a laptop. They're likely not going anywhere, and they clearly already have a laptop...