He's not done well for them, but one of the biggest flops in modern Premier League history is very much hyperbole. PL clubs make awful transfers all the time. Fellaini, Bony, Schurrle, Anderson, Wright-Phillips, Benteke, Cuadrado, Slimani, Mangala, Adebayor (to City), Depay, Schneiderlin (to United), Sissoko, Torres, Batshuay, Carroll, Vero and Shevchenko are among the more expensive ones.
Just saw the elbow on Tadic. If the FA doesn't ban Young after ignoring Lukaku's kick on Bong earlier, I'll seriously start to wonder.