The independent Match Review Panel (MRP) decided that there was no obvious error by Gillett as he should have issued a yellow card and a red card cannot be downgraded to yellow.
The panel also decided that Jeronimo Neumann could not be the subject of a post-match review for simulation.
The MRP issued the following statement:
"The incident involving Ben Sigmund (Wellington Phoenix) in or around the 77th minute of Wellington Phoenix's match against Adelaide United on Saturday evening," it said.
"The MRP has the authority to consider the incident as the player was issued with a direct red card. In reviewing the incident and an Obvious Error Application submitted on behalf of the player, the MRP determined that there was no Obvious Error within the meaning in the A-League Disciplinary Regulations (Regulations), Obvious Error being "a decision by the Referee to ... issue a Red Card when no card was warranted ... being a decision that no referee in the possession of all the facts, including all Broadcast Footage, could reasonably have made."
The MRP confirmed that Ben Sigmund will serve the Mandatory Match Suspension of one (1) match and therefore will be unavailable for this weekend's match against Melbourne Victory. As the MRP did not uphold the Obvious Error Application, there was no basis under the Regulations to conduct a post match review for possible Simulation.
Herbert said the decision showed the incompetence of the referee.
"The referee in the Chelsea-Manchester United game this morning dealt with Fernando Torres, who went down in the same manner as Neumann, by showing him a red card," he said.
"Unfortunately the referee in our game with Adelaide did not deal with the situation competently and we are paying the penalty rather than the player who was guilty of simulation.
"This referee has been in the same situation in a Grand Final and did not deal with it competently there either.
"It is very disappointing for both Ben and the club that he will miss the game against Melbourne Victory, and also wrong that the game is being ruined by players who dive and do not get punished for it."
