I'm going to say no, that wouldn't be correct.
While perfectly fine for both the IC and the unit to disembark at the same time, or one can disembark while the other remains embarked.
What is not ok is for the other to disembark after the vehicle moved.
That is because the 'unit' that the IC was part of has already moved.
Pg 39Or in this case having the rest of the unit disembark/move away.An Independent Character can leave a unit duing Movement phase by moving out of unit conherency with it.
Once the vehicle moves the IC has lost his chance to move.
He had to make that choice with the rest of the unit.