All the time, when I'm fumbling around with other connections on the back of the QC. It's nothing to be afraid of testing; it just power cycles the QC, as you'd expect.
NOT something you'd want to have happen unexpectedly at a gig, of course. (As such: I wouldn't fumble around with other connections on the back of the QC at a gig.) It would have been a good idea to strengthen the spring and/or add a clip as you see on similar Roland, etc. connectors.
If I had a really important gig, I might add a strip of "professional" electrical tape.