Ferguson was furious with Cole's tackle on Cristiano Ronaldo, with the England man only receiving a booking from ref Mike Dean.
"Joe Cole should have been sent off," said the Scot.
"Tackles like that are a danger to players. He went right down the back of his leg and could have done some real damage.
"It is the type of thing Cristiano is facing all the time now but Cole got off with it because the referee was balancing things out after the first sending off."
Ferguson's attack cut little ice with Chelsea boss Avram Grant, who was hugely critical of Dean's performance.
TV replays showed the Nigerian, who left United for Chelsea in an acrimonious £12million deal after refusing to play for the Red Devils, had made contact with only one foot but did have his studs raised.
If that was not bad enough for Grant, who replaced Jose Mourinho as manager earlier this week and was then forced to listen to Chelsea fans sing in their former manager's honour, the Israeli also reckoned Carlos Tevez's opener came well after the allotted two minutes of first-half injury time.
He also felt an already-booked Wayne Rooney should have been sent off for charging into the back of Ashley Cole before his misery was compounded by a debatable penalty converted by Louis Saha after the Frenchman had tumbled theatrically under minimal contact from Tal Ben Haim.
"Sir Alex Ferguson can be more than happy with the referee today," said Grant.
"The referee tried his best but he made three mistakes; the red card, their first goal and the penalty. I am also surprised Rooney was not shown a second yellow card.
"Maybe I am being naive but I wonder what Sir Alex's reaction would have been if he was in my position."
Ferguson agreed that the Mikel dismissal and the late penalty were 'harsh'.
However, given his stance on Cole's tackle and a lunge by the England man on Patrice Evra after the defender had charged into the area which went unpunished, Ferguson felt the decisions evened themselves out.
"It just shows you in a game of that speed and importance, the referee is going to make wrong decisions," he said.
"It was very difficult for him but in the main, I thought he handled the game well."