Per 7.11, If the disc initially contacts the playing field and then becomes out-of-bounds without contacting an offensive player, the thrower must establish a pivot point where the disc first crossed the perimeter line, or the nearest location in the central zone if that pivot point would be in their defending end zone.
In Pull Diagrams, for “Pull Lands In – Rolls OB” on page 2, the top left, top right, and bottom left diagrams should each have a second red dot to indicate the option the thrower has for pivot point.
Credit for this correction: @arijackson @ravi in Ultiworld Discord