So just to clear something up, we had confusion with the following: A unit of normal orcs want to charge a skink unit. The distance between them is 10 inch. My reaction is flee, i roll 4. So the distance is 14 inch. The orc player rolls 11. Does he still add his M value with his roll. Meaning he catches up with the skinks so destroying them? If so does he stop at 14 inches or 15 inches? We have some troubles with the flee and catching up with the unit that flees, it isn't clear in the rulebook we think, it says somewhere: sometimes the charging unit catches the fleeing unit but we will discuss this later, but we can't seem to find it .
Yes, he does add his movement value to the charge roll, as per the rules for any normal charges. If you choose to flee, you immediately turn to face directly away from the enemy and move 2D6 (NOT adding movement value). At this point, the rules for charging a fleeing enemy applies, which is in the charging section of the BRB. Simply put, if he manages to catch up to or overtake your unit, your unit is fully destroyed. He makes the full movement as described in the same section at the end of the Charge section in Movement section of the BRB.
I believe the unit that catches the fleeing unit is also allowed to make a reform if they pass a leadership test.