I have the same problem although not just with photos but also saved video & travelapse. With voice control enabled the dash cam seems to, incorrectly, think a command to take a photo/save a video has been made when in fact it's just something on the car radio or people in the vehicle talking. I was getting a lot of travelapse videos, with the occasional photo & saved video. After initially powering the dash cam via the cigarette lighter I had mine hardwired about 4 weeks ago & bizarrely I've not had any unsolicited travelapse videos since, although I do still get the occasional random saved photo/video.
Turning off voice control would probably resolve the issue, but I do like that feature so will just have to live with the odd random video etc.