Saw most of the Brum game, Matt Smith's disallowed goal looked close but in my opinion he was onside.
I like to think I look at decisions objectively but saw no reason why the goal should be disallowed.
Then I had a discussion with a knowledgeable friend who informs me that a player is offside if his feet are in an onside position but he is leaning toward the goal making his upper body offside, I am sure this was never the case & if it is now then it is ridiculous.