That language is a little less than perfect because an "outer distance mark " is not usually a "starting mark" . The RRS refer to a starting mark.9.3. The Starting Line will be between a staff displaying an orange flag on the main committee boat and an outer distance mark (ODM)
That's the relevant section.
I assume that somewhere in the SI's, the outer distance mark is defined. It will say something like "The outer distance Mark shall be a ........"
If that is correct, then the starting line is defined as being between the orange flag and the mark. If you returned such that you hull was entirely on the pre-start side of a line between the orange flag and the ODM or an extension of that line, and then restarted by crossing that line from the pre-start side to the course side then you have complied with 29.1 and you have started.
I dont suggest that you belabor the point or in any way seek redress (its too late). However, if this is an experienced PRO, they will enjoy learning from the experience. I recommend offering that you may not have restarted properly, so that it is academic, but that you have spoken to other judges and that if the starting line had moved after the start, then your obligation under 29.1 would have been met by clearing the starting line that has moved.
If they felt that this affected the fair outcome of the race then they could abandon the race under 32.1 (c). He should use abandonment rather than general recall. He should always be ready to fly N over class flag immediately after the start.
This will not be the first or last time that a starting mark moves or gets hooked and dragged for his PRO, so the experience is helpful.