Today he appealed the cancellation to the High Court at Auckland, with his lawyer Guyon Foley arguing the penalty was "excessive and inappropriate".
Foley told Justice Anne Hinton his client's track record "isn't a terrible history your honour in criminal terms", but admitted it was "not good".
He said important mitigating information about Drever's mental state and personal circumstances wasn't put before the Real Estate Agents Disciplinary Tribunal when it considered the fate of Drever's licence.
This included him suffering from depression and anxiety, and problems concentrating due to ADHD.
Foley added that Drever had undergone stomach stapling surgery in 2009, shedding a large amount of weight following the procedure, causing physical and mental difficulties.
Drever had considered making the tribunal aware of these facts ahead of his penalty hearing last year, but his then lawyer feared it could be seen as "plucking heart strings".
Foley added that Drever was under immense stress at the time due to the sheer volume of sales he was handling, while also caring for his gravely ill father who is dying of stomach cancer.
"It was a bad patch - can't deny that."
Drever was highly intelligent, engaging and very successful, "but obviously needs to take more care".
"He used the phrase, 'I didn't dot my I's and cross my T's'. He wasn't saying, 'I don't care'. No one wants a complaint. It's a drag both on reputation and a drag financially as well.
"He has paid a high price already in terms of his time out of the profession."
However Justice Hinton questioned why, given Drever's extensive track record and repeated warnings, he should be given yet another chance.
Most people would get "the dickens of a fright" if they were hauled before the watchdog on a single complaint.
"It clearly doesn't worry him. It doesn't matter how many courses he did, he'll be lining himself up for the next [complaints assessment] committee hearing."
Foley countered with the claim that Drever was desperate to prove himself to people, which explained his punishing workload and numerous slip ups.
"Part of the ADHD he suffers [means] he is trying to prove he can succeed.
"It looks like, 'This guy doesn't care, all this guy cares about is money'."
Justice Hinton dismissed attempts to explain Drever's disciplinary history because of his impressive sales record.
"He's one of these people who's just too busy doing deals and making money to take the time to comply with the rules and regulations."
REAA prosecutor Michael Hodge said cancellation was the correct penalty.
Most real estate agents had "lifted their game" when strict new industry standards came into effect in 2009.
"But Mr Drever is simply someone who cannot in my submission make that change."
Justice Hinton reserved her decision.
