Benitez claimed he was waiting to shake hands with the United boss but Ferguson walked past him without doing so.
The Chelsea interim manager said: "I was waiting at the beginning. It's up to him, I was in the way waiting."
Asked why Ferguson might have done so, Benitez added: "Ask him - if you are brave enough ask him. It was his decision. I was ready and waiting. I have some education because I know a lot of people are watching so I know what I have to do."
Benitez did not attempt to shake Ferguson's hand after the final whistle, and explained his action saying: "I was with my players celebrating."
Benitez insisted that Chelsea deserved to win having come from two goals down to draw 2-2 and having been denied victory by an excellent David de Gea save from Juan Mata right at the death.
He added: "We analysed the game and we deserved to win. The first half we made two mistakes and conceded two goals but in the second half we were on top of them and had a lot of chances so it was a good game."
The Chelsea boss also insisted United had had everything in their favour. Asked if United had suffered from tiredness after their Champions League defeat by Real Madrid last week, he said: "I thought you were joking, they play on Tuesday, we play in Romania on Thursday.
"They had everything in their favour, they are playing at home, they played on Tuesday, we are coming from Romania and had to travel again so we did a great game and I'm really pleased with my players."
Benitez admitted bringing on Eden Hazard and John Obi Mikel had changed the match in Chelsea's favour - Hazard responded almost immediately with a brilliant goal - and the Blues boss added: "We knew that we had to change something and we knew Hazard is a player with quality who can make a difference and he had fresh legs as well."
Source: PA
Source: PA