Sigh, this discussion again. Double corner is nothing more than comment flavor that they add to the game. Of course you're going to notice it when if a goal comes from a corner, it always shows up in comments. Instead just look at the amount of corners you get during a game and the % you score/concede. The comments mean nothing.
Just see it as another form of "A timely pass to 'player name' -> goal!/it clips the post/it goes wide/it goes over" Just flavor added to a shot/shot on target, double corners are just random statistics that are added into the comment for amusement.