Saw something at a regional tournament that I've never seen before:
After a turnover out of bounds, a handler picks up, walks the disc back to the sideline, establishes his pivot foot just inside of the sideline (marked by a 2-inch plastic line) and throws a long goal.
The defender calls travel, stating that, when pivoting to his backhand stance, where the toes of the pivot foot were the ground contact, the thrower was no longer in-bounds. The thrower argued that he was in-bounds when on the ball of his pivot foot, or flat footed as he initially was when establishing the pivot, so the pivot placement was valid and the goal stood.
The disc ended up coming back on a travel call to avoid a extended discussion, but I was curious: should the thrower take care to place their foot far enough in-bounds so that all forms of pivoting maintain the whole foot in-bounds? Or is a legally placed foot legal always, no matter how it's pivoted? It seems the current default is to put the pivot foot directly on the sideline, although rule 13.8 seems to indicate that this is actually incorrect (or that the thrower would at least have to have the foot touching at least some part of the central zone along with the sideline).
The annotation to rule 13.8 says that "The official spot is just next to the line (since the line is not part of the playing field), but a pivot foot on the line is also acceptable."
If the thrower had established a pivot at a particular point, and the marker had started to stall, that indicates they were happy with the pivot location and it would be contrary to SOTG to wait until after the throw to call the travel.
Also, the thrower can be touching the OB area, as per 11.3.2.: "A thrower in possession of the disc, who contacts the playing field and then touches an out-of-bounds area, is still considered in-bounds."
In addition, the marker should only call travel as per 1.3.: "only make a call where a breach is significant enough to make a difference to the outcome of the action".
However if the thrower traveled in such a way that it would be called regardless of whether they were now out-of-bounds, then it could be a reasonable travel call.
As always, it is hard to tell without seeing the actual play, but hopefully this gives you some ideas about how it could be officiated.