Manchester United manager Sir Alex Ferguson says referee Mark Clattenburg was "pilloried" undeservedly at Chelsea last weekend.
Clattenburg was at the center of a storm during a tempestuous Premier League clash between the two clubs at Stamford Bridge, which United won 3-2 after the Blues had two men sent off.
The second-half dismissal of Chelsea's Fernando Torres caused the most consternation after Clattenburg harshly awarded a second yellow card for diving. Chelsea's anger intensified after Javier Hernandez then struck the winner for United from an offside position.
Clattenburg was later subject of a complaint that he used "inappropriate language" towards Chelsea's John Obi Mikel by the London club.
Ferguson on Saturday turned his attention to the decisions in the match and the Blues' reaction to them.
"Inevitably you find yourself challenging those 50-50 decisions that go against you," Ferguson wrote in his program notes ahead of his side's game against Arsenal. "That's the human nature of a coach and you learn to come to terms with it so that most of the time you accept the difficulty of a referee's job with good grace and at the end of day you accept that refereeing is the most difficult job in sport and you respect the men who take it on.
"I certainly felt every sympathy for Mark Clattenburg at Chelsea last Sunday. He was pilloried and didn't deserve it. In my mind the officials made two mistakes, one that went against us and one that did us a huge favor, and I don't hold either error against them!"
Police and the Football Association launched formal investigations into the European champions' allegations over Clattenburg, who is reported to have strenuously deny them.
Chelsea submitted a dossier of evidence to the FA containing signed witness statements from players, who allege Clattenburg used a term understood to have been interpreted as racist.
Ferguson felt Torres could have been sent off in the first half for a bad challenge on Tom Cleverley.
"Even if they had felt badly done to on that one, they might have taken the view that overall the referee had done them a favour by allowing Torres to stay on the field from the first incident," Ferguson wrote. "I would have thought Chelsea would have been grateful to the referee rather than going on to give him a hard time and feeling sorry for themselves."
Hernandez's controversial winner secured United's first Premier League win at Stamford Bridge since 2002.
Ferguson added: "It's tough when that happens, but I don't feel too embarrassed when I consider decisions that went against us in some of our other games against Chelsea, one of the factors that had caused us to go 10 years without a league win at Stamford Bridge.
"I know it was a run that got to me at one point and I paid for it with a five-match touchline ban, so I know how difficult it is to rein in your emotions in face of what you consider to be costly decisions that go against you.
"I would just add that in terms of our players in that period they conducted themselves admirably, maintaining their dignity, shaking hands with the referees and generally accepting that you don't get all decisions in your favour."
Some Premier League referees are contemplating boycotting Chelsea games in the wake of the allegations made against Clattenburg, according to former official Clive Wilkes.
"I keep in touch with a lot of the lads and there is such a strength of feeling about what is happening to Mark," Wilkes told The Sun. "I know a few referees who are even talking about boycotting Chelsea games because of all this. Remember, it's not the first time Chelsea have targeted a referee -- there's been Anders Frisk and Graham Poll. And some refs are now saying enough is enough.
"It's no exaggeration to say the refs in this country have never felt lower. They are so disillusioned. They feel vulnerable, feel that they are being left isolated -- that they are getting no backing, no support. They want to speak out themselves but are too frightened, they fear they will be sacked if they go public with their grievances. There have even been murmurings about strike action but that's very much the last resort."
A spokesman for the Professional Game Match Officials Board, the body which regulates professional referees, said there were no links between Wilkes and the organisation.
The PGMOL spokesman said: "Clive Wilkes is in no way connected with PGMOL and his comments have no basis in fact."