[Elecraft] K3 Switching off

[Bill Wiehe]

Experienced something today that I thought I would ask about. I was testing a new microphone in "test" mode with a headphones plugged in so I could listen to my audio. On two separate occasions when I removed the headphones plug, the K3 shut down just as if I pushed the power switch. Pushing the power switch again, everything returned to normal. Anyone have any ideas what might have caused the K3 to shut down?
Thanks,
Bill - W0BBI