Busacca is a referee who knows his players, he watches over his boys, keeps an eye on the ones showing anger, talks to them, warns if he has to. Busacca whistled a lot at the start of the match, too often perhaps, but I'm sure he knew what he was doing.
But then Luis Suares. The Uruguayan is something else. Busacca wasn't going to fall for it again, if Suares falls, he wasn't going whistle. Suares wisely didn't dive, didn't even try to but the one time he was really fouled and fell, Busacca waved it off. And that was an important moment for Ajax. You could say Busacca fell for it again.
Ajax could have won this match, especially after Dynamo lost a man, but they didn't. The old problem what to do when you're one goal ahead in an away match. Consolidate or attack? And Ajax have one or two very mediocre players.