He became famous when, on 19 March 1932, he upstaged Lang at the opening of the
Sydney Harbour Bridge, before a crowd of 300,000 people. He said this was in protest that the
Governor of New South Wales, Sir
Philip Game, had not been invited to perform the ceremony. The Mayor of North Sydney,
Hubert Primrose, an official participant at the opening ceremony, was also a member of the New Guard, but whether he was involved in planning de Groot's act is unknown. De Groot was also said to have later joined the
White Army, another fascist organisation founded in
Victoria in 1931.
Arrest W. J. Mackay, Chief of the
CBI pulled de Groot from his horse, arrested him, and confiscated his ceremonial sword. Initially he was taken to a small police station attached to the toll house on the Sydney Harbour Bridge. Later in the day he was sent to the Lunatic Reception House at
Darlinghurst, where he was formally charged with being insane and not under proper care and control. On the same afternoon de Groot was examined by Eric Hilliard, psychiatrist and medical superintendent of Parramatta Mental Hospital, who determined that de Groot was not insane. The following day de Groot was examined by W.S. Dawson, Professor of Psychiatry at the
University of Sydney, and by John McPherson. Both doctors found him to be completely sane. On 21 March 1932, de Groot appeared before Mr. McDougall, Stipendiary Magistrate, for the hearing of the charge of insanity. Detective Superintendent Mackay gave evidence to the effect that de Groot's actions on the Bridge were those of an insane man. Subsequently, Eric Hilliard gave his opinion, based on his examination of de Groot, that de Groot was sane. The magistrate subsequently ordered de Groot's discharge from the Reception House.
Charges De Groot was subsequently charged with three offences. The three charges brought against him were: • Having maliciously damaged a ribbon which was the property of the Government of New South Wales to the value of £2; • Having behaved in an offensive manner in a public place; and • Having used threatening words to Inspector Stuart Robson in a public place. The charges were heard on 1, 4, 5, and 6 April 1932 in the Central Police Court in Liverpool Street, Sydney before John Laidlaw, Chief Stipendiary Magistrate of New South Wales. While the first and third charges laid against him were dismissed, the Magistrate did find de Groot guilty of offensive behaviour in Bradfield Highway – a public place. He was fined the maximum penalty of £5, with £4 in costs. The Magistrate found that "... the actions of the defendant were grossly offensive, provocative, and clearly unlawful". Later, de Groot sued the Commissioner of police for wrongful arrest, and case was eventually settled out of court with de Groot receiving damages amounting to £69/1/9 (£ or $138.18).
Horse The horse ridden by de Groot at the opening ceremony was a 16.2-hand chestnut named "Mick". The horse belonged to a
Pymble schoolgirl, Margo Reichard, and was borrowed by the leader of the New Guard,
Eric Campbell, from her father Albert Reichard. After the escapade, the horse was initially taken to the Mounted Police Barracks before being returned to its owner. In about 1933 the horse had a fall while being ridden by Albert Reichard, and was put down. == Later life ==