Any team can have a bad day. Under estimated the opposition, trying out new tactics, half the team been suffering from a cold bug, team didn't sleep well in the hotel last night, opposition simply rumbled a couple of weaknesses and took advantage, etc.
Trouble is, once you are chasing a game, you can easily concede more by adopting a more attacking stance.
I guess we will have to put this one down to experience, learn the lessons and hope that our promotion rivals fail to capitalise.
Mustn't panic too much if one result goes against you, but don't think we really have the fire power to get 4 (though it's been done before).