In my opinion that's the biggest drawback to using CO2 - the lack of a second chance.

When I inflate a tire using CO2, the first thing that I do is to blow into the inner tube to give it shape, install the tube in the tire, and finally install the tire onto the rim. Then I check both beads all the way around to be sure the tube isn't caught under the tire bead anywhere. Only then do I use the CO2 to inflate the tire.

Checking both tire beads all the way around can be an enormous time saver.