Per the Premier League Match Centre's explanation on X, the red card was issued as even though the foul took place near the halfway line, goalkeeper David Raya was so far off his line it's conceivable the opportunity for Kudus was clear cut, further emphasised by William Saliba's positioning on the other side of the pitch with no other covering defender.
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DID YOU KNOW?
Arsenal's discipline has been a major cause of concern for Arteta this season as Lewis-Skelly's red card was the fifth time that the Gunners have seen a player sent off in the Premier League since the start of the campaign.
WHAT NEXT FOR ARSENAL?
The red card against West Ham was not Lewis-Skelly's first red card this season as the 18-year-old was sent off last month against Wolves. However, an appeal by Arsenal saw the red card overturned after the game. He will be suspended for this Wednesday's trip to Nottingham Forest.