Ray Allen flops? Did you even watch the video?
I think you need to learn the definition because what Barea did was clearly more of a flop. Flopping is an intentional reaction that is inconsistent with the contact that actually occurred.
When Ray uses his off arm on Barea and he flails his arms back that's a flop, especially when he waits a second for the call instead of immediately getting back into him.
When Barea puts his body into Ray while he has the ball and he falls down, that's much more in the realm of selling the contact. Talk about his height all you want, he's still an NBA athlete not a horse jockey. Some players can withstand hits better than others, and sometimes balance plays a bigger factor than anything, but every player is going to sell that form of contact every time.
It's just part of the game. Falling down is consistent with a player putting his body into you, no matter how hard they do it. That's like saying a guy doesn't have to fall back after taking a charge. Regardless of how much strength or balance you have, it's your job to get that call.
For the record, I wouldn't even call that close to a flagrant 1. If the Celtics were given half the BS as the Heat we'd be 5 time champions.