Lots of people will do instinctive, irrational things during a panic.
Obstructed breathing causes even infants to react by turning their head, or shaking it back and forth, flailing their hands about their face, and when possible, crying.
These instinctive actions are hard wired in us to protect us from suffocation. Unfortunately, sometimes is has the opposite reaction.
It protects babies in case they get a blanket over their face, or an affectionate pet cat gets too close.
As @loli says, it was his brain wrongly telling him wrong information.
Lots of pilots have made the mistake, and it has been portrayed in other movies and some tv shows.
This is a demonstration I think you will find interesting.