The 55-year-old retired match official has told The Sun that he was informed to say he did not see an incident between Steven N'Zonzi and Ryan Shawcross when Blackburn Rovers played Stoke City back in 2011.
Halsey disclosed that he saw the incident but did not want to send N'Zonzi off before being overruled retrospectively.
"I saw the incident between Steven N'Zonzi and Ryan Shawcross and was happy it was not a red card," he said.
"Then, when the assessor came in, he said there was no problem and that I'd refereed very well.
"On the Monday we had our get-together with referees at Warwick University and I was told, 'Look at this' and I was still happy with the decision.
"I was told to expect a call from the FA compliance department, which I duly got.
"When I got the call I said I was still happy - but they said my bosses weren't happy. I was under pressure to say I hadn't seen it.
"I was furious but no matter what industry you are in, you do what your bosses say.
"So he was charged and got three matches."
Halsey said: "I was furious, I didn't want Steven N'Zonzi charged. I was not happy.
"I'm honest but what can you do when the management tell you to do something?
"You can't speak out but you should not be put in that situation anyway.
"It's obvious why they do it, as some get charged and others don't."