Free Reform post pursuit?

Not quite. If you are referring to a unit that declares a Flee! charge reaction after a charge, it depends on a Ld test.

• BRB p. 23: "If, for whatever reason, a unit completes a charge against a fleeing enemy, move the charging unit(s) into contact with the fleeing enemy as described earlier and then the fleeing unit is run down by the chargers. Most of the unit is hacked apart or trampled to death, and the few survivors head for the hills with no intention of fighting further — remove the entire unit as casualties.
  
  A charging unit that destroys fleeing troops in this way will often find itself pulled out of position and vulnerable to enemy counter-charges. Accordingly, we allow the charging unit to attempt a reform by passing a Leadership test If the test is failed, the troops are so overcome with hacking at the fallen corpses that they do not have the chance to reform. If the test is passed, the unit immediately makes a reform manoeuvre (see page 14). In either case, the unit cannot move further during this Movement phase."
  

If you are referring to an actual pursuit after a failed Break test, then you can choose to take a Ld test to restrain pursuit, and not catch the enemy, in which case (if successful)  you can reform. 

• 
  BRB p. 56: If the losing unit failed its Break test, it must flee, but the winning unit now has a choice of actions. It can pursue the foe, seeking to solidify the victory by scattering or slaying the survivors of the fight. Alternatively, the victorious unit can attempt to stand fast, using the precious seconds earnt by its victory to reorder itself and prepare for other fights to come. Restraining from pursuit in this manner requires a degree of organisation and discipline that does not come easily in the heat of battle.
  
  
  Accordingly, if you wish your unit to restrain pursuit, it must first take a Leadership test to see whether or not its leaders have been able to keep it in order. If the test is passed, the unit conforms to your wishes and holds position, and can choose to reform once the defeated enemy has fled. If the test is failed, then no amount of bellowing or bullying will be sufficient to keep the unit in order - they elect to pursue the enemy anyway.

However, if you pursue the enemy after a Break test and catch him, you cannot reform. 

Yes, but it is often confused. Hence, I was already adapting my answer, before I could read your post.