It´s a fact than in every sport where a referee is involved, they try to even out their decisions. they often know imediatly after they´ve made a call that they were wrong but have to stick to it.
there was the corner for arsenal which clearly was a goalkick (they showed busacca´s face and you could see that he wasn´t happy with his decision), there was the foul on messi which should have been a penalty or freekick, so he decided to even the hole thing out. it wasn´t even a bad call, just very harsh.