Next on the list is "Moccasins of Geronimo."
Encountered Guards: Observatory
Number of Unencountered Guards: 2
Rooms not Entered: Room of the Three Gargoyles, Heart Room, Shrine, Room of Harmonic Convergence
Notes: There are several reasons why any of the remaining rooms could have held the two remaining guards. Some people say that the Room of Three Gargoyles could have had a guard because the temple guard door was slightly ajar during Olmec's temple rundown. A photo is accompanied below, courtesy video posted on youtube.com by ChargerTheWolf. Some people think either the Heart Room or Room of Harmonic Convergence had a guard because guards were common in those rooms. Other people believe the Shrine held a guard because the room was directly next to the room with the artifact.

My Thoughts: All of the rooms appear to be good possibilities because all of the explanations seem legitimate. It would be nice to know where the half pendant was in this run, because that would help point to where the guards were. Even without the half pendant, I have made some deductions about the run, and the most logical places for the last two guards to have been are the Gargoyles and Heart Room.
-- I agree that the cracked door in the Gargoyle Room is a hint that there was most likely a guard in that room. In a few other episodes, cracked doors are seen during Olmec's rundown that held guards during the run.
-- When Mitchell spun the sundial in the Observatory, there were a number of sound effects going off at once. The temple guard theme was playing, and the noises for the opening door(s) also played at the same time. It is hard to discern, but I believe there were two door sound effects- one for the Heart Room and one for the Treasure Room. If both of those sound effects played, that meant the Heart Room easily could have held a guard while being an extra room to enter en route to the Treasure Room (similarly to "Electrified Key of Benjamin Franklin," among many others).
-- Unlike most people, I don't think there was a guard in the Shrine, and here is why:
One important note about this run is that during Olmec's temple rundown, the block between the Pirate's Cove and the Dungeon was already up. This may suggest that, if Mitchell had gone into the Shrine, the only door that would have opened would have been the one that led down (like in "Edmund Hillary" and "Mush Pot Hat"). The Shine, therefore, would not have been the room directly prior to the one with the artifact. Also, I'm not 100% sold on the idea that the Treasure Room would have led to the Shrine, because it seems unlikely for the path to have diverged between the Shrine/Dungeon and Swamp/Tomb/Dungeon. For that reason, I am hesitant to believe there was a guard in the Shrine.