The panel said he would have been sacked over the incident if he had not already left the force.
It was found that Mr Vickers actions had been dishonest, deliberate, and had the potential to damage police confidence.
Community resolution orders are an informal agreement between a complainant and an alleged offender, and for it to be valid, it had to be issued to Mrs Gather should have been spoken to directly, accepted responsibility for the offence and signed the paperwork.
The report concluded that Mr Vickers did not follow this policy when issuing the resolution.
Mrs Gather previously said the order had included agreeing not to take items from the park in the future, and looking into Bradgate Park’s status as a designated site of special scientific interest (SSSI).
Picking mushrooms is illegal in sites of special scientific interest, which are protected areas of land or water.
At the time of the incident Mrs Gather had said she felt the actions of Leicestershire Police had been “a bit excessive” – although this was not assessed by the misconduct panel.
The hearing, which took place in October, was told the force received a call from Bradgate Park Trust about a woman who was picking mushrooms at their park in Leicester on 8 November 2024.
On 25 November, Mr Vickers went to her home address and advised her husband that he would issue a community resolution, an informal agreement between a complainant and an alleged offender.
Her husband signed the relevant paperwork before the officer left.