'Parliamentary Privelege' mate, they lie often and it's perfectly legal. Politicians can technically raise a complaint of 'contempt of privelege' if a lie is serious and caused "an improper interference with the free exercise by a House or a committee of its authority or functions, or with the free performance by a member of their duties as a member." As some may argue this lie did. In our history it has happened exactly zero times (meaning, it's toothless).

https://www.aph.gov.au/about_parliament/house_of_representatives/powers_practice_and_procedure/00_-_infosheets/infosheet_5_-_parliamentary_privilege

Making it illegal sounds great to me though, I don't believe any reasonable person would say that you should be able to lie in order to "debate matters of importance freely" which is the current line of horseshit we are expected to believe. If we start asking loudly for it now - we might get a watered-down version in about 20 years give or take, if the federal ICAC is anything to go by.

More eloquent info: https://www.sydneycriminallawyers.com.au/blog/should-lying-in-parliament-be-a-crime/