Seagulls blame ref and effort
But he went on to slam his own side's performance, saying: "It's a shocking result - for a club with any aspirations to stay in the Championship to be losing to a League Two club isn't good enough.
"It's a poor, poor result and everyone has got to look at themselves," he seethed.
McGhee also reserved some scorn for the official, Trevor Parkes, who turned down two penalty appeals for challenges by Joe Hart and Kevin Sharp on the tricky Jake Robinson.
McGhee said: "I think decisions went against us - I think it was a shocking decision not to give the penalties for Jake Robinson, and we even had other penalty claims when people were pulling the jersey off Mark McCammon."