Like Cany said, it could be your button sticking. What I would suggest is to take a cotton swab, dip it into some rubbing alcohol (squeeze out excess liquid), then swab around the button. Then, push down on the button and move it around a bit. Hopefully, once you do that a few times, it'll stop auto-firing.
Haven't used the Caliburn G although I have looked at it. Of all the pod systems I've used, the pods seem to leak onto the battery and causes all kinds of problems. I prefer using my eLeaf iPower 80W with an Aspire Triton 2 tank. That's been my rig of choice for quite a few years now and haven't had any issues at all.