Yeah I've seen a few of these pop up and I'm surprised, risk isn't taken lightly in the military. These guys of all people should know how fast it can go from sweet to shit, let alone their commanders.
I think it's incredibly likely that they are actually strapped in.
Most air crew know the severity of the situation. Regular Soldiers might feel free to take risk, but I suspect those who are flight crew appreciate the risk of the situation. It's not hard to imagine that their safety straps are behind them.
I, as one who has to write up risk assessments and think about the stupid shit subordinates pull off all the time, really hope they have taken this basic step. It seems impossible, but I must remind myself, stupidity knows no bounds.