WTF just happened?

So I was walking around Rostok, after dark, looking for the damn entrance, and I fell ass over tits into a ditch. Didn't take any fall damage and it seemed as if I was stuck underneath some furniture (?) And stuff at the bottom of the ditch. As I am trying to jump up and find a way out, the screen goes blank and I am wondering where my last save point was. Only to get the white circle tunnel animation on the screen and pop out on a random piece of cement in the middle of nowhere, miles from Rostok... was that a glitch, is it a bug or a feature?