Return of Reckoning

Quick question, did not find the answer through search and I have to admit I am too lazy to try it (especially if someone already has the answer)...

Can Ain't Done Yet tactic boost HoTs that have already been cast on a target once the target drops below 25% HP ?

Do the HoT ticks get boosted when he is below 25%, or does it need to be cast when he is below 25% for the boost to occur ?

Any ticks when below 25% will count no matter the hp on cast.
Be pretty mean if it didnt on a hot class.

Thanks, that is what I was hoping for and wanted to verify. (but my expectations were not necessarily high...)