Most of the post-match talk at West Brom surrounded a mass melee after the final whistle involving players, officials and stewards - with Royals winger Jobi McAnuff seeing red for his involvement in an incident with Albion midfielder Youssouf Mulumbu.
McDermott felt the situation was "unnecessary" and criticised stewards for "definitely over-reacting", while promising to review television footage of the incident before considering an appeal against McAnuff's dismissal.
But predictably, he was more comfortable talking about the Berkshire club's historic achievement.
"For me the key is the football, we're in the last eight and I'm proud of all the players," said McDermott.
"It was a great night, a fantastic cup tie.
"You talk about the FA Cup losing its shine but you saw tonight what that meant to two sets of players and supporters.
"It was a fantastic night for everybody in a Reading shirt and everybody connected with the club.
"It's put us back on the map a little bit and I'm pleased about that.
"We're one step away from Wembley.
He continued: "To share a touchline with Martin O'Neill is great for me personally. To play Villa, fantastic.
"I don't really have any fear about facing anybody, full stop. I just enjoy the occasion."
Robert Koren set the wheels in motion by putting Albion into a sixth-minute lead, before Jimmy Kebe equalised for Reading just three minutes later in a blistering start to the encounter.
Koren grabbed his second immediately after the restart thanks to a horrible mistake from Royals keeper Adam Federici, who allowed the midfielder's shot to squirm under his body and over the line.
The gaff looked destined to settle the tie until the third of four scheduled minutes of injury time when Brian Howard found the net to send the visiting support into raptures and the encounter into extra time.
And there was more misery for the home faithful when Gylfi Sigurdsson curled a 95th-minute winner into the top corner from 25 yards to settle a remarkable cup tie in fitting circumstances.
But the controversy did not end there as the post-match brawl brought an unsavoury end to the night.
Albion head coach Roberto Di Matteo did not want to comment on the incident, insisting the Football Association can deal with it.
But the Italian could not hide his disappointment at bowing out of the competition.
"I'm destroyed," he said.
"We were in the driving seat and it wasn't a dangerous situation (Reading's late equaliser). We just needed to clear the ball.
"We put a lot of effort in and we worked very hard to win the game, then we come away with nothing.
"We just didn't defend the second and third goals, we gave them gifts to win the game.
"We threw it away."
Albion must now turn their focus back to securing promotion from the Coca-Cola Championship, and Di Matteo added: "We have to pick ourselves up to get going again on Saturday."
Source: Team Talk
Source: Team Talk