...it's illegal because it's a blind screen and a screen out of the line of vision of the player being screened requires a player to be set with more distance than a regular screen. With that said, late clock flat screen down the sideline is a very typical bball action in short clock situations and it is on a teammate to yell that it is coming. When players get clocked on screens like that it is typically their teammate at fault. I'd guess Louisville just called a short clock play just to run it and that's why they did that but it is by no means dirty.