CO2 per se won't cause a problem. If the inflator gadget gets the pressure too high, that would be a problem.
Failure analysis is important in preventing repeat flats. Always look at the hole in the tube. Is it a small cut? Just a puncture, as with a thorn? Abrasion? Seam split? A break in the rubber at the base of the valve? Then take a look at the tire. Is it rough on the inside? Trapped gravel or sand? Glass flakes poking through? Remnant thorns?
And then there's mounting. New tires especially can be stiff, and it's really easy to get the tube caught between the tire and the rim as you push the last area of the tire over the edge. I usually put a little air into the tube to help keep it out of that space. Be careful with tire tools, as they can also pinch the tire.
How do I know? I've made every mistake listed above.
