@RidgeTop
1. Every epic Sci-Fi movie (Star Trek, Star Wars, Terminator, Alien series and so on) contain scientific inaccuracies. Even the recent ones like
Gravity,
Interstellar and
The Martian are flawed on that field. Am I bothered? Not at all. You cannot take Sci-Fi movies too seriously because you wouldn't enjoy them at all.
2. Charlie Holloway doesn't take his helmet off on LV-223 surface. If he did that he would have been dead, like Ford says during the landing:
Only if you're breathing through an exhaust pipe. CO2 is over 3 percent. Two minutes without a suit, you're dead. He does take his helmet off being inside Engineer pyramid knowing that the air (result of terraforming) is cleaner than Earth's one. It's a minor scene in the movie. Its explanation is sufficient enough. Besides, sometimes you have to sacrifice scientific accuracy and rational characters behaviour for a sake of the story itself. Deal with it. Charlie takes his helmet off? Not a big deal. Main protagonist in
Interstellar enters the black hole and ... survives. Try to beat that
.