John Tomlinson was praised for being "cool and calm" in a crisis during a Traffic Commission hearing to decide if he should keep his HGV licence.
Half a million YouTube fans have viewed the clip showing Mr Tomlinson's 40-tonne tanker pushing a Renault Clio at high speed along the A1(M) in Yorkshire.
Yesterday's hearing, before North West Traffic Commissioner Beverley Bell, was told the accident happened when the Clio driver attempted to undertake Mr Tomlinson's tanker in an "ill-advised" manoeuvre.
Sean Joyce, Mr Tomlinson's solicitor, described how Rhona Jane Williams, a vet from York, was joining the south-bound carriageway of the A1(M) at junction 44 when the incident happened at around 8.30am on January 13.
Quoting her statements to police, Mr Joyce explained that her lane of the slip road merged into the middle lane of the motorway.
He added: "She saw Mr Tomlinson's HGV in the middle lane as she came off a slip road on to the carriageway.
"She was effectively performing an undertaking manoeuvre as she joined the lane." Ms Williams told police she felt a "bump" as the vehicles came together and her car pivoted 90 degrees.
Mr Tomlinson remained unaware of the incident and continued driving until a motorist in a 4x4 pulled ahead of the vehicles and began flashing his hazard lights.
Mr Joyce said: "Mr Tomlinson remains unable to offer any explanation simply because he was unaware of the collision.
"Taking into account he was driving a 44-tonne tanker, the Clio is a relatively small car. He was sat high up in the tractor unit which was extremely well insulated.
"He simply did not hear anything, see anything, or feel anything." Mr Tomlinson, from Clitheroe, Lancashire, brought his lorry to a stop on the hard shoulder and only became aware of Ms Williams in the Clio when he got out of the vehicle.
He tried to free her but the door was jammed so he reversed his tanker about three feet to release the car.
The tanker was empty as Mr Tomlinson, a commercial driver for 29 years, was returning to his depot after making a delivery of silica sand.
Both drivers luckily emerged without injury and the collision was initially treated as a "damage only" incident by West Yorkshire Police.
But the investigation was reopened after the YouTube clip came to light in March.
Mr Joyce said the investigation included a reconstruction of the incident which proved that the Clio was outside Mr Tomlinson's line of sight.
He added that the tanker's tachograph showed no breach of driving time limits.
Forensic examinations also showed his speed limiter was functioning and there was no mobile phone use at the time of collision.
Mr Tomlinson's employer, Cheshire-based Arclid Transport, initially allowed him to continue driving. But he was suspended on full pay in March when the YouTube clip was brought to the attention of the Traffic Commissioner.
Peter Gavin, solicitor for Arclid, told the hearing all the company's vehicles were now being fitted with close-proximity mirrors to enable HGV drivers to clearly see the front of their vehicle.
Traffic Commissioner Ms Bell said it is now the law for these mirrors to be fitted on new vehicles, but the recent legislation was not retrospective.
She told Mr Tomlinson: "It is absolutely clear that you could not see the Clio as you were driving.
"What you found when you pulled into the hard shoulder must have come as a complete shock and I think what you did, in reversing your tanker to release the Clio, was of huge credit to you.
"You showed, in my view, coolness and a clear head. I feel it is entirely inappropriate for me to take away your licence." Ms Bell added that the case illustrates the dangers of HGV blind spots and urged other firms to follow Arclid in installing close proximity mirrors on older vehicles.
She also said it was "regrettable" that West Yorkshire Police did not investigate the matter fully until after the YouTube footage came to light two months after the incident.
After the hearing, Mr Tomlinson appeared close to tears as he spoke of his relief. He described the pressure of the investigation as "indescribable".
A statement, read by Mr Joyce added that a thorough investigation had shown Mr Tomlinson was completely innocent and wholly vindicated of any wrongdoing.