Richards, who resigned his post as director of rugby at Quins following the original ERC hearing into Tom Williams' supposed blood injury, pleaded guilty to fabricating a wound and organising the subsequent cover up.
That original independent disciplinary committee had found Harlequins and Williams guilty of misconduct after Williams' 'injury' allowed fly-half Nick Evans, who had earlier been substituted, to return to the field of play late in the match.
"I'm a little bit shocked, a little bit surprised by it all. It seems a little bit disproportionate," former Lion Richards told Sky Sports.
"I took full responsibility for it. It was a farcical situation, it really was.
"It didn't pan out particularly well on the day. Everybody looked at it and thought, 'That's unreal', which is what I thought on the touchline as well."
The original hearing held on July 2, 3 and 20 imposed no sanction on Richards himself but instead suspended Williams for 12 months and fined Quins 250,000 Euros (of which 50 per cent was suspended for two years) for the actions of their employees.
ERC, who run both the Heineken and European Challenge Cups, were unsatisfied with the findings and lodged an appeal.
The result saw the fine handed out to Quins increased to 300,000 Euros (payable in full by December 1), and Richards and club physiotherapist Steph Brennan banned for three and two years respectively.
ERC also stated that they received evidence of four other occasions in non-ERC competitions in which Richards and Brennan had fabricated a wound and that they would be encouraging other governing bodies to impose a similar sanction on the two men.
Williams had his own suspension cut to four months, meaning he is eligible to play again on November 20.