Another way that Options Market Makers are able to achieve perpetual naked short positions (and avoid the 13-day FTD reporting requirements), is to repeatedly swap their naked shorts with another Options Market Maker. This is separate from retail trading, and has to do with shares shorted in the course of a MMs own proprietary trading. It just takes two to collude.
This method has been discussed both here and in several blog articles on the topic, especially the (now-defunct) website
"Counterfeiting Stock 2.0" (still readable through the "Wayback Machine" at archive.org).
The reason this 2nd naked shorting scheme might break down during a share dividend event is unequal short holdings leading to the "
hot potato" syndrome: No MM wants to be the one left holding the bag, so they break and cover as rapidly as possible.