Nicola Urquhart, 49, revealed a lack of CCTV in the hours after he vanished means the airman could have walked or been driven out of the area he was last seen in.
She says the new information “changes everything” in the search for her son, who was last seen on a night out with friends in Bury St Edmunds, Suffolk, in September 2016.
Detectives investigating the airman’s disappearance believe he climbed into a bin and was transported to a waste site around 30 miles away.
Specialist search teams spent 27 weeks scouring the landfill near Cambridge last year but found no trace of Corrie’s remains.
In a lengthy statement on the Find Corrie Facebook group, Mrs Urquhart said: “Initially I was told by the RAF that no one would have been able to leave this area [Horseshoe] without being captured on this CCTV.
“The senior investigating officer (SIO) then confirmed this fact.
“We have now been told that this is not accurate.
“Corrie could have left in a vehicle after 7am and could have walked out in any direction after midday.
“The reason for this is the CCTV was only collected in the immediate area up to midday.
“After 7am not one of the huge number of vehicles in the area have been identified or traced, this is why he could leave in any of these vehicles and there was no CCTV collected in this area after noon - this is why Corrie could have walked out.”
Following his disappearance, it was initially thought Corrie, who was based at RAF Honington, may have tried to home.
A search from Bury St Edmunds to RAF Honington was carried out, but Nicola believes other areas need searching.
She said: “We know that when Corrie went missing there was a massive search carried out from Bury to Honington this search covered the area that if a person was to walk the police have guessed - slightly more to it than a simple guess, I am using simple terms - which would be most likely.
“Suffolk MIT have drawn a line of the most direct way to walk “as the crow flies”. This area has been searched.
“However, when I have been with Corrie, including the week before he disappeared he drove from Honington to Bury on each occasion by driving along the A134 and along Green Ln.
“April [his partner] has also confirmed this is the way Corrie would usually drive.
“The search for Corrie walking back to Honington only covers the right-hand side fields of this road with only the verge on the other side being searched.
“There have been a couple of other areas searched on this side but the majority has not been searched passed the standard search when searching a road.”
The £2m hunt to find Corrie was shelved earlier this year after police admitted having “no realistic lines of enquiry left to pursue”.
Officers from Suffolk Police said his disappearance would now be passed to a cold case team.
Any credible new information will continue to be followed up by officers, however it may never be known what happened to Corrie.
Mrs Urquhart, who is critical of Suffolk police throughout the post, added that she believes that Corrie was never in the landfill.
She said: The entire area that had rubbish dumped on it from September 19 when Cell 22 was opened to September 30 when it was closed was searched and rubbish from Bury on the dates that Corrie went missing was found but not one single trace of Corrie or his clothes was found.
“Rubbish was found in Cell 22 from the exact date Corrie went missing and could be confirmed it was from Bury. I believe this all shows without reasonable doubt that Corrie was never in this bin or landfill.”
She added: “I will be looking to have areas searched but this will take time, should I need help again with searching I will ask.
“I would beg anyone that felt they had information but due to the constant messages from the police that Corrie was in a landfill felt it wasn’t relevant to please get in touch with Suffolk police.
“We believe that this new information changes everything.”
Detective Superintendent Katie Elliott of Suffolk Constabulary said previously: “It is extremely disappointing that we have not been able to find Corrie.
“I can only imagine the strain Corrie’s family have been under over the past 18 months and I thank them for their patience and understanding.
“Whilst the investigation has drawn to a natural conclusion we will continue to work with the family to provide answers to their questions and help them understand what may have happened.”