There's a reason why so many large format shooters are humble, easy going people.
Life should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming– “Wow! What a Ride!”
I've been shooting LF for the past 5 months now. In a short amount of 5 minutes time, I've done every single one of those mistakes.
1. exposed before putting the filter on
2. exposing with the preview engaged
3. removing the holder before replacing the darkslide
4. removing the wrong darkslide
some other ones
1. exposing on the timer mode, when i thought i was set at 1 second.
2. forgetting to set the aperture, leaving it at its widest setting
3. forgetting to decare my wooden field camera to australian customs. (This one could have gotten really messy)
4. forgetting to remove the back lens cap from the lens (This one took me a full minute to trouble shoot)
5. forgetting to BRING a cable release
Didn't happen with LF but it happened to somebody I am very acquainted with : being in the countryside, no photographic shop within too many km, Saturday evening, lost the only one cable release on a field, gone back to that field, desperately looked around in the grass for the shutter release, it must be here, I must have lost it somewhere here, long search, no results, gave up.
Cable release was in a pocket of the too-many-pocketed vest.
As a wise man once said: "Cable releases and lens caps can turn invisible at will." So true.
And on the subject of mistakes: Even my photography teacher who had been using a LF camera for more than 20 years managed to forgot to close the shutter before pulling the darkslide just now. I think, making mistakes is a big part of LF photography
Luckily, it was only relatively cheap 4x5... if that happened with 20x24 or some other ULF, I wouldn't want to be anywhere near for a few days...