The counterplay is that he literally just used one of the strongest teamfight damage ults in the entire game on a single person and he's out of position, so now your team kills him in 1/4 of a second. Also, land a barrel combo on him and he'll die. Not even kidding, if you're a late game GP, you drop your ult so he's in the center and land a barrel combo on a Twitch and he's dead from full health. Also, if any of your allies had been close enough to him, they'd be able to see him and kill him.
Offense for Twitch - Infinity Edge, Statikk Shiv, Rapidfire Cannon, Executioner's Calling, and Death's Dance
Defense for GP - Ninja Tabi, 250 health from Trinity Force
I don't see the problem with that Twitch handily killing that GP who was running away.
Wow a full build twitch killing a gangplank without any defense items in a few hits unheard of....
You had a solid 2 seconds there to flash and escape. Get caught out by an assassin that's as fed as the Twitch? You have half a second at best to react, if that. I have gotten near insta-kills on Talon since the patch.
You people will think anything is burst because it kills you fast. No. Late game, between two targets itemizing nearly fully offensive, burst is when a rengar pops out of stealth, takes over half your health with one auto, then finishes you off with his Q. Nearly instant. Of course full dps on a squishy target will hurt, but burst is different at that point in the game.