Personally, I don't think one could be charged. All the different degrees of assault under KRS stipulate that physical injury (or an attempt of) must occur. There might be a case (albeit a bad one) for a charge of wanton endangerment.
I can imagine holding someone at gun point. If they were to charge towards me, then that would lead me to shoot. If they run, that would change the situation. If the threat of their attack is gone and I'm holding them for the authorities to arrive--if they turn tail and run, running after them would turn my position from a defensive one to an offensive one. That, I would think, would potentially increase the risk of criminal or civil charges.