The Magpies denied Reading their first Premier League victory at the time with a late and controversial Demba Ba goal.
The striker, who moved to Chelsea recently, punched the ball into the net with seven minutes to go to rescue a point for Alan Pardew's side.
McDermott was fuming that neither Marriner nor his assistants spotted the infringement in the September clash.
The West Midlands' official was at the centre of another handball storm a few weeks ago when in charge of Liverpool's FA Cup clash at Mansfield.
Once again, Marriner allowed a dubious goal to stand when Luis Suarez clearly handled the ball before scoring his side's second in a 2-1 victory.
However, the Premier League has taken the surprising step of placing Marriner in charge of Reading's return fixture at St James' Park tomorrow.
And while McDermott says he has forgiven Marriner for his blunder, he hopes he gets the big decisions right this weekend.
"There is no point feeling aggrieved about what happened at our place because it's in the past," declared McDermott. "But everyone knows the referee got it wrong.
"In fact, it was the same referee who was in charge for the Liverpool game when he missed the Luis Suarez handball.
"They were two blatant ones and it's unfortunate he missed them both. They were genuine mistakes but there is no sense of revenge on our part this weekend. We just hope the officials get their decisions right."
Ba's handball was all the more galling as Royals were the better side on the day and deserved to take three points.
Jimmy Kebe and Noel Hunt gave Reading the lead on two occasions but Ba's brace robbed them of a victory.
However, McDermott stressed: "We played very well on the day and we deserved to win that game, there is no doubt about it.
"Having said that, West Brom were probably aggrieved they didn't beat us last Saturday so it all evens out over the course of the season."
Reading will fly to the North East with renewed confidence after their sensational 3-2 home win over West Brom last weekend.
Now McDermott's men go to St James' Park searching for their first away win of the season knowing a victory could also lift them out of the relegation zone.
"West Brom gave us a useful three points which takes us closer to the teams above," added McDermott. "But we've got a big job to do and the first part of that is picking up a win on the road.
"The main thing is we concentrate on the game itself and making sure we are right on the day. There are plenty more twists and turns to come this season and the main thing is we give ourselves the best possible chance of staying in this league."
New signing Stephen Kelly is set to make his Royals debut at St James' Park, while fit-again Mikele Leigertwood and Hal Robson-Kanu are both in contention.
Meanwhile, pressure is mounting on ex-Royals boss Pardew at Newcastle following their disappointing start to the season.
"I know Alan really well, he brought me to Reading," stated McDermott. "We both want to win and we are expecting a tough game.
"People tell me it's a good time to play Newcastle and we will soon find out whether that is true."