I suppose that if you don't use the external views a lot, then this odd error may go unnoticed.
Hadn't seen it myself until you mentioned it.
Have tried switching the key commands for the peris in Commands_en_cfg but this doesn't completely rectify the problem. The correct periscope now extends in external view but the internal view through the scope is still wrong
Might have a look in the camera dat file if I can pluck up enough courage but I'm hoping someone knowledgable can come up with a complete solution.
BTW: I think this sort of stuff would probably be better off posted in the WAC 4.1 Sticky thread.