No reason to assume that - the openings on the sides of the Flight Deck do not line up with the turntable - you yourself had to place that shot at an angle. A door from the back would not have that issue.
I just added it that's why! Sorry, I thought I could sneak it in before you responded. As to your point:
Yes technically we should have seen the clamshell doors (if from an aft facing door) but then again technically we should have seen the observation gallery (if from a side facing door). Instead we see neither, just a blank wall behind the shuttle.
TOS-R tried to fix this by adding the observation deck above the shuttle but they couldn't even get the height consistent in the 2 episodes it appeared in.