Bard Charm-Killing Question

[indiscriminate_hater]

I've been doing a bit of bard charming for exp recently and I can not find an answer to my question. If you charm a mob and have it beat down another until they are both near death, and then finish them off yourself, what percent of the exp do you receive from each mob?

To specify exactly what happens, I keep the initial mob charmed until either one is at 5-10% health (the other should be around same health if mobs are of ~same level). I don't deal any damage this entire time to the non-charmed mob because of aggro transfers when the charm wears off. Once this point is reached, I invis to break charm then DoT the two mobs to death. Does the 50% exp penalty apply to the non-charmed mob even though my pet is no longer charmed? Is there a 50% exp penalty on the initially charmed mob because I didn't do over 50% damage to it?

I can't seem to find any answer on the wiki or the forums. Confirmation via looking at my exp bar is difficult because my bard is level 57, and the bar sometimes doesn't even move after I kill a dark blue mob completely by myself. Anyone have an answer?