Yup, same thing happened to me, but I'm not sure if the watch caused it or if it was the razor blades I stuffed in my jacket...
Edit: Seriously though, this isn't Apple's problem. There will soon be 2 million+ people walking around the country wearing an Apple Watch, and if your alarm goes off due to it, then your alarm is broken (not the watch). Your alarm is designed to detect stolen goods and it's failing because the Apple Watch is NOT stolen. Don't blame Apple, blame alarm manufacturers for making a defective product.