The flashpoint occurred when Boyle approached his former employee immediately after the Steelmen's 2-1 Clydesdale Bank Premier League win. The Motherwell chairman shook hands with Brown but put his other arm around the former Scotland manager's neck and whispered in his ear and a spat ensued.
A statement on the SFA's website, www.scottishfa.co.uk, read: "At a meeting at Hampden Park, the Scottish FA Disciplinary Committee found Craig Brown, the Aberdeen manager, guilty of misconduct by behaving in a disorderly manner towards the Motherwell chairman, John Boyle, during their match at Fir Park on April 2."
It added: "The committee decided to impose a censure and warning as to Mr Brown's future conduct.
"The committee also found Mr Boyle guilty of misconduct by behaving in an inappropriate and inflammatory manner towards the opposing team's club official.
"The committee decided that a fine of £2,500 be imposed on Mr Boyle and that he be severely censured and warned as to his future conduct."
Brown accepted the decision, telling STV: "I respect the individual members of the disciplinary committee and I accept their censure.
"They acknowledged the level of provocation to which I was subjected."
Brown and Knox, who left Motherwell to take over at Pittodrie in December, have launched a £25,000 legal action against the Lanarkshire club over unpaid bonuses for the club's Co-operative Insurance Cup run.
The pair led Motherwell to a quarter-final win in October but had left the club, where they had not signed a contract, before the semi-final.
Source: PA
Source: PA