[GAMEPLAY] Potentially Harmful Rengar Bug

Unfortunately, I do not have gameplay, and do not know how to replicate. However, I was playing a game as Rengar and as I was using an ability I noticed my abilities were empowered with only 3 stacks. Soon enough I realised I could infinitely spam all of my abilities. All of which were empowered and had no cooldown. The stacks increased but I never lost my empowered. It is unknown that if I had died would I have lost the empowered; we lost shortly after, before I could test. I hope that this cannot be easily replicated, as this could cause some serious grief. It may have something to do with being CC'd while having 5 stacks, as I was ulted by Warwick moments before (I was half-way through an empowered Q leap, when I was suppressed).

EDIT: Was able to accidentally do it again in Customs. Still not sure on the cause. This time around, I ulted and killed the Ashe with the standard combo (Empowered Q, E, W, Q) then I attacked the Kog'Maw. He chased me into a bush and I Q leaped onto him (0 Stacks), immediately after I had 1 stack and was empowered, again able to infinitely spam my abilities. However, this time as I reached 5 stacks and used the 5th it reset and was no longer able to spam. Even if it does wear off, this still allowed several empowered attacks leading up to the actual empowered strike.