Dutch Uncle
* Tertia Optio * Defend the Constitution
None of the letters and correspondence Cortes himself wrote during the events of the invasion say that the Mexica thought or implied he was a god.
That is a huge oversight to forget writing about
IMO, this is a case of taking a few incidents and inflating them into mass belief.
Consider that when the Spanish showed up with their giant canoes, horses and firesticks, the natives considered them superior beings, if not gods. The first time the natives saw the Spanish bleed, they'd know they were dealing with humans.