Example (not specifically about Rest but vape detectors in general):

Several things can trigger a false alarm, including aerosols from cleaning products, emissions from cooking stoves in kitchens, and vibrations.

Spray-on deo, hair spray, baby powder, perfume etc are all likely to create false positives yet the hotels just charge instantly from a single detection event.

https://vapecould.com/blogs/news/vape-detector-an-in-depth-look-at-the-pros-and-cons