The Buddies levelled from the spot after Emilio Izaguirre was adjudged by referee Bobby Madden to have fouled Esmael Goncalves in the box, when it looked like there was little or no contact.
This after Lennon's side had a good penalty appeal turned down moments from the interval when the ball appeared to hit the arm of Celtic striker Georgios Samaras.
They also had the ball in the net from Gary Teale's cross only to have it ruled out for Paul Dummett's challenge on Hoops keeper Fraser Forster.
"For our penalty, I am led to believe it was outside the box, they say these things work themselves out throughout the game so if it was we got a wee break there," said Lennon.
"But we were delighted to at least take a point out of the game, we deserved it."
As for the penalty that was denied his side, Lennon said: "There is a fine line in the laws of the game, was it a deliberate handball or did the ball play him?
"Let's make it simple, if it hits his arm or hand then it is a penalty, then there is no mistake.
"I was a bit irate (when Dummett was penalised for the push on Forster).
"The way I have seen it and the way the replay showed it, Izaguirre pushed our player into the goalkeeper. So it is either a penalty for us or a goal.
"Managers, players, supporters, we can all have bad days and I suppose it is the same with officials.
"We know the difficult job they have and once they sit back and watch that I believe they will pick up one or two things."
Celtic were reduced to 10 men when Victor Wanyama was shown a straight red card 10 minutes into the second-half for a challenge on Paul McGowan, who went on to score the home side's penalty.