The first couple times through the cycle... .I was willing to believe that he really was just confused, that the back-and-forth was just part of an (albeit angsty and idiosyncratic) decision-making process.
But I bought into the narrative that ultimately each time through, he really was learning something new, making his decision more concrete or final. Sure, some people need to try on one shirt, then the other, look in different lights, etc
But by the third or fourth it was like... .ok, even if he IS gaining new information each time around the roller coaster... .that's dysfunctional, people don't go back and forth this many times, he shouldn't need this many tries to get all his experimental info!
And by the fifth or sixth it became clear... .there wasn't even a process, he wasn't getting any NEW information or learning from the cycle. So it became harder and harder for him to convincingly spin it as just his own waffling but still ultimately progressing decision-making process.
There was no progression forward at that point, just side to side motion. And when it reached a point that his turning of wheels in the mud could no longer be spun as forward progress, he ran away in shame... .
You pretty well described my thoughts during the stages of my time with the ex.