re: Here's a recent event in Mexico they can start working on.
How high up were they? How fast were they moving? What were the weather conditions? How long did the remain in view? Did they make any noise? Did they do anything other than seem to hover in a group? Who else witnessed them?
My Spanish is minute, to put it mildly, so I don't know if the voices on the tape answered any of the above, but I would be surprised if they did. And they do look like a group of balloons to me. What kind of balloons were they compared to that they could declare they were not? All I see on that little bit of video tape leads to me think they were balloons.