I THINK I AM THE FIRST TO REPORT THIS. IT OCCURRED AFTER THE MASS LAST NIGHT BUT MANY MAY NOT HAVE WATCHED THIS!
If you wish to see this live, go to the video of the Mass last night I have posted below this post and go to hour 2, minute 12, second 59. He actually falls, at hour 2, minute 13. Fortunately and by God's grace he fell into the chair that he would use to meditate before the image of Our Lady of Guadeloupe. If he had actually fallen on the floor, I believe His Holiness would have been injured as he was falling backwards.
Here are screen shots of the moment. In the video, you can hear the thousands outside the basilica actually gasp and scream!