Mr Engler was left with injuries to his left side and was diagnosed with post-traumatic stress disorder following the attack.
Mr Feargrieve was criminally convicted of assault by beating in December 2019 and was sentenced in 2020. Judge John Zani at the time found that Mr Feargrieve used “excessive force”.
He said: “You really should not have behaved in the way you did. In my view you lost your temper. It was excessive.”
The Oxford University-educated lawyer was ordered to pay more than £2,200 in fines, costs and compensation.
Mr Feargrieve, who pleaded not guilty to the charges, subsequently lodged an appeal to the crown court but ultimately withdrew the action.
Mr Feargrieve, who is also a solicitor, was rebuked by the Solicitors Regulation Authority in 2021. It said the criminal conviction undermined the public’s trust and confidence in the solicitors’ profession.
The solicitor watchdog ordered him to pay its £300 investigation costs.
Attacker was unregistered barrister
Mr Feargrieve was already an unregistered barrister, meaning he did not hold a licensing certificate to practise in England and Wales.
He was called to the Bar in 1996 but did not complete a pupillage, the final stage of training before becoming a barrister, according to the BSB.
Mr Feargrieve, who has spent the past decade working as a self-employed consultant to investment funds, did not attend the hearing. He has two weeks to respond to the BSB’s requests to pay £1,560 in costs.
A BSB spokesman said: “Barristers have an obligation not to behave in a way which is likely to diminish the trust and confidence which the public places in them or in the profession, even when not practising.
“The tribunal’s decision shows that Mr Feargrieve’s actions leading to his conviction were a clear breach of that duty and the sanction reflects the seriousness of this.”