Fergie is under the impression that chief of referee's Keith Hackett had asked Halsey to reconsider his decision which would have led to Terry having to serve a three game ban starting with the game against United at Stamford Bridge this wekend.
However, Halsey is believed to have refused to reverse his decision that Terry's tackle on City striker Jo had been unprofessional conduct.
"I understand Hackett told ref Mark Halsey to rescind the card and he wouldn't. So now he is refereeing in League Two this weekend," fumed Fergie.
"I do not understand how this has happened. If it had been a Manchester United player, Hackett would not have done this.
"This is going to have to happen all the time if a referee is considered to have made a mistake."