Really no idea how it happened. Our whole team turret dived them, I AA'd from a distance a bit before Rocket Jumping onto a couple of low targets, AA'd some more, heard the announcer say "QUADRA kill!!!!", notice my ulti come off cooldown in that same second, and that it was enough to blow up the remaining enemy.
[LoL favourites: Janna, Syndra, Rumble, Fizz, Ezreal, Miss Fortune, Katarina, Volibear, Ahri, Lee Sin, Kog'Maw, Sejuani, Wukong, Nunu, Swain]
Got my first penta as a free week Mordekaiser, ulted the enemy Tristana who was fed as hell since my team sucked and delayed their baron boosted push for a while before they came back again and killed us all.