Former Cherries winger Matt Ritchie stuck a late equaliser to rescue a point.
Benitez said: “I thought that the game was nearly lost but it was a great goal from Ritchie.
“I'm happy for that but disappointed because we could get three points the way we were playing and managing the game.
“We could win the game."
Ritchie opted against celebrating wildly in front of his own fans in the final seconds but Benitez was delighted for his player after he scored against his old club.
He said: “In football these things can happen.
“He was doing well for us in defence and to score against his former team in the way that he did, I am sure he is happy and at the same time he's made all the Newcastle fans happy."