In general, Brych adapted his style to suit the Friendly status of the match, showing fewer cards and ignoring some lesser fouls, although he missed a few opportunities to play out advantages. And in light of the two cautions he did issue, Van Bommel should probably also have seen a yellow card in the first half. I also felt Cahill was offside in the build up to his goal.
An issue I have noticed with Brych is that his use of the whistle is not the best. Whatever the level of infringement, he always gives a long-ish powerful blast. He could 'make the whistle talk' a bit more; used properly, different whistle tones can be a very useful tool for the referee.