Is it a bug or a normal thing ?

So few days back i had this battle and i had no time to put a post in here
to see of it's bug or a normal thing.

ScreenHunter_1746 Nov. 21 23.06.jpg
Here on the picture i just show the teams but watch the whole battle in HERE
When Iza the Fanged hits Torrent Fiend and stunned it, even tho Iza dies a few attacks later. The Torrent Fiend stayed stunned until the end of the battle.

So is is because it needs to perform an attack to skip the round and then the stun is removed or is it some kind of bug?