Benitez left himself open to charges of defending the indefensible.
"The boy knows he was wasting time," he said. "Hazard was frustrated and trying to get the ball back. We cannot change the situation. We are disappointed because we lost a player. The best thing is to move forward."
Benitez said that Hazard's actions would be dealt with internally by the club, but reacted angrily when he was accused of attempting to condone Hazard's actions.
"I do not know what you expect from me," he said.
"Do you think we are not disappointed with the situation, that we do not regret what happened? Do you think they have not apologised? They have done it so what can we do now? Do you want to change things? We cannot.
"The player spoke to the boy and he said sorry because it was a mistake. We know it was a mistake but we talked with the player and the boy so what do you expect?
"As a football club we know there was a mistake," he added. "We will talk to the player. We will deal with this internally. He was frustrated and wanted to get the ball back. We will analyse and we will have to wait to see what happens."
Hazard's unsavoury actions are the last thing Chelsea need in a season already including the John Terry racism scandal, the Mark Clattenburg affair and the unpopular sacking of Roberto Di Matteo.
Police interviewed the player and the 17-year-old, but have decided no charges will be brought. However, the Chelsea player seems certain to be hit with at least a five-match ban.
Speaking after the game, Hazard said: "The boy put his whole body onto the ball and I was just trying to kick the ball and I think I kicked the ball and not the boy. I apologise."
In a bizarre twist the ballboy was named as Charlie Morgan, the son of Martin Morgan, one of Swansea's directors.
He was led away from the pitch clutching his ribs after the incident, but was described as "fine" afterwards. Chelsea invited the teenager to their dressing room where Benitez said "the pair apologised to each other".
Hazard added: "The ballboy came in and we had a quick chat and I apologised and the boy apologised as well, and it is over. Sorry."
Swansea manager Michael Laudrup highlighted the red card as the moment he knew his side would meet Bradford at Wembley.
He said: "They lost the belief they could do it after the red card. You could see when he was sent off that they were finished. After the red card, I saw the reaction from both teams and knew that was it.
"To be in a final for the first time is fantastic. If you add that we have beaten the European champions over two legs then it is incredible.
"He's (Hazard) a great player but has made a huge mistake. When he watches it back he will regret it."
Fellow professionals were split today on whether Hazard had done much wrong, with many sympathising with the Chelsea player.
"Both the kid and Hazard were in the wrong," wrote Michael Owen on Twitter. "Not having Hazard tried to hurt him though. He just tried to toe poke it out of his grip."
Tottenham winger Gareth Bale agreed.
"Unbelievable decision by the referee to send Hazard off," he wrote.
But Manchester United defender Rio Ferdinand believes Hazard deserved to be shown the red card.
"I'm not the authorities but in my eyes its a red for all those asking," said Ferdinand. "Us players do put refs in bad spots at times unfortunately!"