Capacitive touchscreens are tricky. You want them to be sensitive enough to work quickly when touched, and sometimes through gloves or when wet. But if they're

Capacitive touchscreens are tricky. You want them to be sensitive enough to work quickly when touched, and sometimes through gloves or when wet. But if they're too sensitive, or don't recalibrate well to dynamic conditions, you start to get false touches. Another root cause is usually a noisy ground from a power supply, but I would hazard a guess that's not a problem for a standalone watch.