can leaving a truck in drive or reverse then switching off and leaving the vehicle cause any damage
No. It can however make you look a pillock if your batteries aren’t man enough to start your engine and you’ve lost your air.
I did it one night in a Daf. In the morning the engine wouldn’t start as I was in gear but couldn’t change to neutral as their was no air.
I sometimes drive a small Merc ,the key thing wont come out if its stopped in drive.There should be a module on this subject.
Ive been driving my first auto for a couple of months now, didnt know it can get stuck in gear if left in drive 
Ive must have been bloody lucky as I always forget to take it out of drive
Drift:
Ive been driving my first auto for a couple of months now, didnt know it can get stuck in gear if left in drive
Ive must have been bloody lucky as I always forget to take it out of drive
It will only happen if there isn’t sufficient air to change back to neutral when you switch the ignition back on.
If the truck senses it’s in gear then it won’t start. And you can’t build your air to change into neutral because it’s in gear. Chicken and egg type situation.
m1cks:
Drift:
Ive been driving my first auto for a couple of months now, didnt know it can get stuck in gear if left in drive
Ive must have been bloody lucky as I always forget to take it out of driveIt will only happen if there isn’t sufficient air to change back to neutral when you switch the ignition back on.
If the truck senses it’s in gear then it won’t start. And you can’t build your air to change into neutral because it’s in gear. Chicken and egg type situation.
Good to know 
My Premium will put the box in neutral when the engine is off anyway and it won’t start if the selector is on D.
On the Actros, if you switch the engine off when it’s still in gear, when you come to start up again, although the selector is in gear, the 'box is in neutral, must default to neutral when the ignition is switched off.
If the switch is returned to the neutral position then back into gear, it’s OK.