United came back from three goals down to emerge with a point from Stamford Bridge, thanks for two contentious spot-kicks and a Javier Hernandez header.
While Chelsea manager Andre Villas-Boas felt the second penalty, given for Branislav Ivanovic's foul on Danny Welbeck, was harsh, Ferguson was in no doubt whatsoever that both decisions by referee Howard Webb were correct, and even claimed his side could have been awared two more.
"We had two penalties in the second half which were justified. I think we could have had four penalties," said the Scot, who also complained that Blues debutant Gary Cahill should have been sent off for hauling down Danny Welbeck after 10 minutes.
"It's a sending off. I don't blame Howard Webb, I blame the assistant. I can't understand that."
Despite his grievances Ferguson reflected on a memorable recovery, although he agreed it still represented dropped points.
"It is two points dropped, but we played so well apart from the 10 mins after half-time," he said on Sky Sports 1.
"It's not easy coming back from 3-0 down. That's a massive effort."