Jon Sullivan lost the seat of Longman, north of Brisbane, after holding it by 4.3 per cent.

He made national headlines on election eve after he questioned why Robert Murphy would wait two years for his disabled son to see a specialist.

However, it was revealed today that Mr Murphy had not been honest during the radio public forum that led to the debacle.

His family had not waited two years for help, as he claimed.

Mr Murphy went on ABC Radio this morning to explain why he lied.

"I thought it was [two years]," Mr Murphy said.

"I mistakenly said it happened over two years.

"I didn't plan [the question], I didn't think it through properly. I shouldn't have said what I said."

Mr Murphy said the time period was his only fib and his son, Bailey, did have a disability for which he had waited to seek help.

When asked if he accepted he may have contributed to Mr Sullivan's loss, Mr Murphy apologised.

"If I am blamed for it, I do apologise. But it wasn't my intention," Mr Murphy said.

He said he did not mean to embarrass Mr Sullivan.

"I just needed a bit of a hand, not only just for my son but for hundreds of other people that are the sort of similar situation where they don't know who to go to or who to turn to to get help, to make sure that they can get help for their children.''

Labor had reportedly expected to win the seat of Longman, believing the 20-year-old LNP candidate Wyatt Roy's age would count against him at the polls.

Mr Sullivan's response to Mr Murphy drew immediate scorn from the audience and made front page headlines the following day.

"It's taken two years to take my son to the doctor to get him diagnosed because we don't have the money to actually go and pay a specialist ... so that he can get the proper help that he needs at school," Mr Murphy said.

Mr Sullivan replied: "What parent would wait two years to get a child who they believe has a disability ... "

Mr Roy won the seat with a 3.87 per cent swing.