These vehicles are extremely complicated. Unless it becomes a persistant problem I wouldn't worry too much about it. While I was driving in EV mode last year the green battery icon greyed out on me one day similar to the gas pump icon. Happend twice I believe with only a couple thousand miles on the odometer. 14,500 miles on the clock now and have not experienced it since. Unless your Chevy dealer sells and services Volts on a daily basis I would not let the techs tinker with the electronics unless you feel comfortable in their ability in doing so.
Just tell yourself it was only a "hiccup" not a "glitch".
2012- Crystal Red Tintcoat
EVSE- Eaton L2 (16-amp)