The 18-year-old was sent off by referee Michael Oliver late in the first half when he caught Wolves' Matt Doherty with a deliberate trip.
However, it sparked mass confusion, as a challenge of this nature would almost always be punished with a yellow card.
The fact Doherty was brought down as Wolves looked to break away following an Arsenal corner left some suspecting whether the red card was due to Lewis-Skelly denying a goalscoring opportunity, despite the incident taking place 90 yards from goal.
But the Premier League Match Centre account on X clarified the reason.
"The referee's call of a red card for Lewis-Skelly was checked and confirmed by VAR, who deemed his challenge to have been serious foul play," the account wrote.
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Oliver's decision left Arsenal's stars incensed as they surrounded the official in an unsuccessful attempt to get the decision overturned.
Such was the aggressive nature of Arsenal's protest, Jurrien Timber picked up a booking.
"That's one of the most ridiculous red cards I've ever seen," Groves said at half-time.
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"It's a trip. Everybody in the stadium took a breath. Everyone went, 'What!?'
"They couldn't believe it. They'll try and justify it some way. They'll say serious foul play. It isn't.
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"It's a professional foul. Yellow card. I think the VAR - Darren England - is frightened of Michael Oliver. Because Oliver is higher up.
"He should be saying, ' Go and have a look'. I'm absolutely amazed. If that's a red card, the game is gone.
"It's not a straight leg tackle. It's not a studs up tackle. It's a trip."
It is not the first time this season Oliver dished out a controversial red card to an Arsenal player.
He was the one who brandished a second yellow card for Leandro Trossard during the Gunners' dramatic 2-2 draw with Manchester City in September.
The Belgian's offence was that he kicked the ball away to delay a restart following his foul on City's Bernardo Silva.
More to follow...