The Dons led 2-0 after just 16 minutes through goals from Christian Ramirez and Scott Brown before Alfredo Morelos pulled one back for the champions before half-time.
It took Rangers until the 81st minute to equalise when James Tavernier scored from the spot after Aberdeen defender David Bates was judged to have fouled substitute Fashion Sakala.
“It’s not a penalty kick,” said Glass. “It is a little bit of a coming together, it isn’t a penalty kick. I am happy with a point but I think we could have walked away with more.
“I thought we were brilliant defensively and carried a threat as well. I would have been happy if you had given me a point at the start of the day, but I am pretty disappointed with the way it has ended.
“The boys put in a performance like that, the work rate and effort. Rangers have a brilliant group of players but we get undone with that and it is very disappointing."
With captain Brown producing a man of the match display in central defence, Aberdeen followed up Saturday’s win over Hibs as they look to recover from a dismal run of form which had placed Glass’ position under intense scrutiny.
"We were excellent throughout but Scott is a pure leader,” added Glass. "He has played out of position in the last game and a half but he has shown what he is capable of, why he is at the club and why he has been what he has been for the last 15 to 20 years
“Everybody wanted to shoot them down. Everybody wanted to shoot myself down, shoot the whole group down. But the group has shown what they have got. I have never doubted it the whole time.
“But you can’t get carried away because we come here and nick a point. We need to go and beat Hearts on Saturday. It gives us a platform to build on. The platform is the work rate and effort of the players. You saw that from them tonight.”