Didn't watch the game, and haven't watched Everton much this season, but certain styles of play fit the league better and certain styles of play fit the champions league better.
United, especially in the last few years under Fergie were masters of the Premier League, but didn't quite play as well in the Champions League, though they did make a few finals. Ferguson knew exactly how to play teams in the league and exactly how to win the league. Europe is different.
It could be the opposite for Martinez and Everton maybe the style they play is more suited to the European game.