The human brain can only consciously think of 4 things at once. In a stressful situation the brain will function less effectively and that will decrease the number of things it can process. Using this information we can build "muscle memory" by repetitively performing a task. This allows your body to perform the act without thinking about it.
With that being said are you checking your air pack off wrong? Sounds like a crazy question right? Well most of us are setting ourselves up for failure.
Just about everyone takes the air pack out, puts it down on the floor or leans it forward on the seat with the top of the bottle facing you and checks it out (see picture). This is creating bad habits. We turn on the bottle and we trigger the PASS device with our left hand (the opposite of what we use when we wear the pack), and check the by pass valve and buddy breather with our right hand (again the opposite hand). This may not sound like a big deal, but if you do it everyday during the academy and everyday on duty then that is how you will react under stress. In an mayday or emergency situation your body may keep reaching with the wrong hand to perform these tasks. Not because you don't know what you're doing but because that is the basic programming you have. Now you have to stop thinking about how to get out, where you are, what to say in the MAYDAY call and think about turning you PASS device on. Or you may never activate the PASS or turn on the by pass valve because your brain doesn't have the capacity to think about it.
Try checking your pack out while wearing it on your back and use the hands you'd be using in an emergency. Checking it off this way creates proper muscle memory and will allow your brain to think about the things you need it to. I know it's different and you may get some strange looks, but let people know why. It may save their life or your life one day.