Gareth Barry headed home in injury time as the champions snatched a last-gasp 1-0 win to deny the bottom club what would have been a hard-earned Barclays Premier League point. McDermott felt Barry illegally jumped on the back of one of his players as he leapt to reach David Silva's cross but referee Mike Dean saw nothing untoward.
When asked about the winning goal, McDermott said: "Absolute joke."
Dean had been similarly unmoved when Jay Tabb went down in the area after a collision with City youngster Karim Rekik during a second half Reading counter-attack.
"We have had that a few times this season and even the Tabb penalty - it was a penalty," continued McDermott. "We have had three or four of those, we have had a handball goal against us and an offside goal against us - all of which have cost us points."
Despite McDermott's frustrations after a resilient defensive display, City were the superior side throughout.
The hosts created numerous chances but lacked a cutting edge and manager Roberto Mancini was again left to bemoan his side's wastefulness.
The Italian said: "I think we deserved to win but when you are in the last two or three minutes of extra time, it could be difficult.
"These games, if you don't score in the first half when you have a lot of chances to score, I think they can be strong.
"They played well, they defended well, for 90 minutes with all players behind the ball. We didn't find space to score. When you have one chance, you have to score. In the end, I am happy with the victory but we had a big problem."
Source: PA
Source: PA