The sleeve of my coat caught on the gear shift while making a left turn and threw it in reverse while on the freeway.

It made a grinding noise and I yanked it back into drive.

Other than the noise nothing bad happened.

No, but for as long as I've been driving manual cars they've had gates to prevent that very action. (1995)

Not mine (Honda Jazz). But you physically can't do it, as the reverse gear has no synchro and won't mesh unless stationary.

It can be done, but it's neither easy nor a good idea: https://youtube.com/watch?v=ARJENV0qGdY

You'd certainly struggle to do it by accident.

it should make a loud grinding noise though,