Cyriel Dessers and Nico Raskin got the goals for the Light Blues, with first-half controversy at Easter Road surrounding another Raskin effort which appeared to have crossed the line.
Speaking to RangersTV at full-time, the head coach said: “I am disappointed to only get a point, I thought we dominated parts of the game, we just weren’t ruthless enough especially with the number of chances we had so I am disappointed we finished the season off with a point.
“The decision was baffling, why wasn't it given in the first place. I don’t want to get myself in trouble but that can’t be happening in football. It was clearly over the line. I saw it as it happened, I saw it at half-time and I saw it after the game and my mind has not changed. It was certainly a goal.
“It changes the dynamic of the game, but also within that even when it got back to 1-1, we still have a lot of chances, and we have got to be more ruthless when we get into that final third.”
On his past few months as head coach, Ferguson continued: “It has been an amazing journey for me, it has been a proud moment, not just for myself but my family and my friends and I have loved every single minute of it. I have tried to make a difference, I think I have, so we will just need to wait and see what happens over the coming days.”
He praised the players for their efforts in the final few months of the campaign, but says improvements have to be made ahead of the new season.
Ferguson continued: “One thing about the players is they gave me 100 per cent. It is obviously different from the way they were playing before, and it is not ideal when you come in at this stage with only three months to go.
“You want to spend a full pre-season and work up to what way you want to play and be a bit flexible in your formation so one thing, but they have given me everything.
“The quality at times has to be better, I can't hide away from that, and we need to get better moving forward because we need to be challenging and winning trophies because that is what this club is built on and hopefully next season that can be the start of the process.”