Confirmed in 0.53.103342. I'm stuck in veteran.

This even seems to be the case in single player. AI have flashlights on, but they don't illuminate the area like the player's does.

A few updates later and this is no longer a problem. Could a mod mark this as resolved or ignored or something?

This happens every time for me. Any time I'm prone holding a pistol and I switch to a rifle with the switch weapon key, the character stands up, goes prone again then holsters the pistol and takes the rifle of his back. It's super annoying, but it's still awesome to be able to use pistols effectively in Arma.