Saturday’s match saw the Diamonds consolidate second spot after winning their fifth match in row, whilst Falkirk lost ground on the final promotion play off spot after Queen’s Park picked up a point at Alloa Athletic.
Speaking to the Falkirk Herald, the 46-year-old quickly picked out the positives from the display.
“I feel like we are close, I really do and after today I feel like we're nearly there,” he said.
“Last weekend was a high and today for the players in the changing room it will feel like a real low, but it isn’t.
“The endeavour and effort on show coupled with the quality we did show in moments gives me great hope.
“We came away to a tough place and scored two goals, that should have been us putting at least a point on the board but we conceded three and have ended up not taking anything out of it, despite having the best chances.”
He added: “I have so many positives to take.Two goals down most sides would have folded. But we didn’t and we showed confidence. “For a team that has had such a rough year the character shown out there gave me real hope that things have changed for the better.”
The head coach did aim his frustration at the match referee Duncan Williams, and his sides error-proneness creeping in throughout what was a battling display.
He said: “We still made too many big mistakes that we really should be able to stop doing and change.
“I think that in the first half we didn’t really play the way that I was expecting us to play, and I think that Airdrie, who are playing well at the moment, were really on top in the second period of that half.
“The second goal they scored was one that you can’t really do anything about, it was just a well worked goal from a team full of confidence.
He added: “The frustration for me also lies with what happened within the match that isn’t in our control.
“For the first goal the move begins from a free kick that wasn’t a foul in my opinion.
“At the end of the game the same thing happened. Aaron Taylor-Sinclair was fouled and they go on and score, in that instance we didn’t get the decision so things like that are annoying.
“I felt like the referee gave many free kicks in the same areas outside the box which was infuriating because they weren’t fouls. You can go in for a challenge without fouling someone but he didn’t seem to grasp that,” he bemoaned.
Callumn Morrison was guilty of poor finishing on the day, missing a header from two-yards at 0-0 that was easier to score than to miss, the forward also missed another decent chance - but Rennie was quick to quash any direct criticism of individuals.
“It’s hard to start picking out an individual, we win and lose as a team,” he said.
“We didn’t lose today because of that and I will never criticise one player. He put himself in the position to miss and the next time if he does that again, I am sure he will get his goals.
“The same goes with the defence, there were moments that individuals made mistakes but they work as a unit, if one makes an error the rest need to stand up and cover them,” he added.
Falkirk’s performance certainly had fight and the head coach praised the start to the second half, and once again reiterated that he believed his team were close to turning a corner.
“In the second half we came out much stronger and we scored immediately which was a great response,” he said.
“We started playing a bit more like I would have expected us to and I think there is so much the players can learn from this match and improve on.
“Airdrie have been on a very good run winning five in a row and they are on a high, we pushed them all the way and we missed so many chances.
“We’re so close. Having that confidence and fight tells me the other stuff we need can come quickly and we need to take those elements into next week.
He added: “One or two additions would make a big difference. By this time next week I am hoping to have some new faces in the door.”
The Bairns now travel to bottom club East Fife, who are cut eight points adrift after a 2-0 defeat away to Dumbarton.
Speaking about the match, Rennie was looking forward to watching his side at Bayview after his first match in charge was called off due to poor weather conditions in Methil.
He said: “It wasn’t the start I expected and it will be nice to go back to play out a full match.
"We know what we have to do to win the game and it is important we take three points."
When asked about injuries he confirmed Paul Dixon has had surgery on his wrist and cannot play for another week or so due to wearing a cast, but the defender is match fit.
Goalkeeper Robbie Mutch has also returned to light training.