Law 10.4(b) A player must not stamp or trample on an opponent.
Under the IRB Sanctions for Foul Play, Law 10.4(b) carries the following sanction entry points: Low End: 2 weeks; Mid-Range: 5 weeks; Top End: 9 to 52 weeks.
The independent Judicial Officer, Jeremy Summers (England), heard evidence and submissions from Evans, who pleaded guilty, from Ospreys Team Manager, Andy Llloyd, and from the ERC Disciplinary Officer.
In upholding the red card decision, the Judicial Officer stated that the incident involved at least two stamps which connected with McCarthy's head and which resulted in a serious facial wound.
Mr Summers also stated that there was no place in the game for conduct of this kind - a view which Evans himself accepted during the hearing.
The Judicial Officer determined that the offence was at the top end of the IRB sanctions for offences of this nature and selected 16 weeks as the appropriate entry point. As there were no aggravating factors, he reduced the suspension by four weeks due to the player's guilty plea, good conduct and remorse during the hearing.
The period of suspension runs over 13 weeks as the Judicial Officer chose to take into account one week during the Six Nations period when the player would not have played. Evans is therefore free to play on 21 April 2014.
Both the player and ERC have the right to appeal the decision.