In response to an Official Information Act request, police have admitted the crash file was never examined, and a Transport Agency employee who blamed the truck driver was simply taken at their word.
"The original footage and explanation were supplied by an employee of the transport operation centre, which is the group which looks after CCTV footage for NZTA. It was supplied in good faith," police public affairs chief Karen Jones said.
However, having received the footage for several adverts with different crashes, the police communications staff failed to verify the information passed to them about the truck driver causing the crash while texting.
Police received the crash footage from NZTA in November and published the videos online in January.
"Unfortunately, there was a simple misunderstanding internally within police which meant one of these videos was captioned incorrectly," Ms Jones said.
"Police have contacted the truck driver and victim involved in this particular crash ... and both have accepted an apology from police for the incorrect caption."
It was supposed to simply be a "symbolic crash" for educational purposes, where none of the drivers was recognisable, Ms Jones said.
Mr Cathcart, a former policeman, said when the video was released on YouTube that police were misleading people and unfairly blaming the truck driver.
The female driver who caused the accident was charged with careless driving causing injury.
The officer who was the lead investigator on the crash case told the Herald there was never any suggestion the truck driver was on his phone and there was nothing about that in the crash file.
How it unfolded
*July 26, 2012: Former policeman Simon Cathcart's car rolls six times after another vehicle slams into him, pushing him into the path of a truck on SH1 in South Auckland. Mr Cathcart cracked his spine. A female driver was later charged with careless driving causing injury and pleaded guilty.
*January 2014: In a road safety video, police wrongly blame a truck driver for using his cellphone and causing a crash. The online video highlights the dangers of texting while driving.
*This month: Official Information Act request uncovers that police communications staff took the word of a New Zealand Transport Agency employee and never examined the crash file.