Why was his tomb not desecrated?
House Storks Key Sun Fish
Looks like the actual location of the tomb changed.
Maybe it was actually meant to be somewhere else or thought to be somewhere else.
So, according to your documentary his tomb was meant to be for Ay and other Historians believed it may have belonged to a previous Pharaoh (Royal member) with Tut's death being so unexpected.
He may have actually been thought to be buried elsewhere if that is the case.
I think if it was a tomb that was re-used (not Ay's) then it may have already been known therefore not of such interest. The robbers would have been looking for an "opportunity" rather than if the tomb belonged to so and so.
And even if it was Ay's...
Divine intervention of the Gods were strong I would say.
I still think the "Gods" or "divine intervention" kept this one little tomb safe with the KEY card being there. (Not my own personal belief).
"Signs" would have played a key role in it remaining hidden too - like following a certain star during a full moon in the shortest month of the year only to end up at a dead end or the Dead Sea. (Or a map).
Either the signs were wrong or none were given.
Ancient Egyptians were quite superstitious - seeing an Owl was seen as "evil", floods meant fertility (I think), the color "blue" kept the "evil eye" at bay etc and they had many many Gods etc.
Ra being the Sun god and God of all gods.
I think in regards to Tut's tomb and looking at it now - literally no signs were given and that is why it remained hidden.
However....
If say, a flock of birds was spotted near the tomb when raiding them during those times, an Egyptian would have been absolutely mortified and would have seen it is a bad omen or a pure place of evil.
Other "signs" may have been followed back then too.
So, although there is no real proof, there is still that possibility.
"Signs" tie in with the KEY card.
Later...ancient maps would have been used and maybe hieroglyphics, but with Archaeologists not tomb raiders.
Possibly his tomb may have thought to be closer to water or a coastal area so it was not found due to that notion.
His tomb is close to the Nile, but then so are other Pharaohs and Queens.
What is interesting, however, is both Ay and Tut are buried in the "non royal areas" of the valley.
Ay I understand, but not Tut.
All traces of both were meant to be wiped out in history for whatever reasons only a few things turned up with his name on on it including a clay pot or cup found near Ramses II's tomb, this kept the idea alive he was still buried there somewhere.
Still trying to work out the significance of the FISH although "2" still sits fine, but there must be more to it or it would not have turned up.