The Hibees looked all set for the win after Liam Craig's double until United's spirited comeback, which started with a strike from David Goodwillie which culminated in Brian Graham's last-minute equaliser.
The point ensured McNamara's men avoided a fourth consecutive defeat. and moved up into fourth place.
McNamara said: "I was delighted with the way we came back into the match. They went 2-0 up with the penalty after not really doing anything in the match. That was the frustrating thing.
"It was self-inflicted but they showed good character to get their just rewards in the end.
"I think you seen the determination and drive to keep going after much has been made of the past three weeks when we've had a few defeats. I thought we deserved a draw."
There was controversy on the half-hour mark as United pushed for the opener.
Nadir Ciftci struck a long ball forward for Gary Mackay-Steven which prompted Ben Williams to run off his line before mis-kicking his attempted clearance.
Williams then grabbed Mackay-Steven who was about to home in on goal from just outside the box but the assistant raised his flag for offside and the visitors breathed a sigh of relief.
"We were a bit disappointed with the decision when Mackay-Steven was clean through in the first half," McNamara added.
"I thought their keeper could have walked at that point.
"Gary was touch and go for offside so it was a big decision."