You keep using that word. I do not think it means what you think it means.
Ahhh....my misspent youth...
If a unit attempts to move directly into a hex occupied by an enemy unit, it can be Op Fired upon in its hex of origin and is treated as if it was moving.
Just to be clear - it can only be fired upon in its hex of origin if the FIRST hex it attempts to move into is enemy occupied.
If the hex of origin is Foxholes in Open Ground, is the unit 'moving in the open'?