Alarm code typically specifies height at which alarm strobes will be mounted. The door in the first picture is "identified" by a strobe carefully placed at the correct heigth....no matter that the strobe is completely out of sight at that location!
I would say someone was doing exactly what the prints shown, looking for some extras money when the final inspection revaled this little gem of engineering genius. A good example of trades not communicating.
Sven, move to the head of thre class! The wall was an outside wall; last summer this space was covered (but not truly "enclosed"), and the new roof blocked view of the strobe. The "precision notched purlin" is, in fact, a modified I-beam.
As for 'critters.' well, I arrived on day #2 of the job to find a squirrell eating the heart of my print! Don't you hate it when that happens?