A real early-in-the-UEFA-Cup kind of match

protesting

Johannesson showed 6 yellow cards and four were for protesting. If so many players protest a ref's decision, maybe his decisions were worth a dissent. Or maybe the way he controlled the match was not good enough. Players tend to protest when they feel the ref is not up to it.
Later on in the match though, he twice allowed a player to yell at him. Suddenly that wasn't an offense anymore.

little things

It's not that Johannesson made big important mistakes, he has a good eye, but there were a lot of little things like off sides and free kicks or the fact that he didn't give a free kick that irritated the players. It was first this and then that with Johannesson

Match

Nurnberg could not control the match, so what they did was wait. They waited for a mistake and when AZ sider Opdam was replaced by a player called Koenders, suddenly a big gap in the defense showed itself. A gap so big that Nurnberg managed to score twice within three minutes in exactly the same way.