Having been booked, Calafiori fouled Facundo Buonanotte, but it was the Argentine who was booked for protesting.
Arteta later said: "I haven’t seen the action but I got really worried when that happened because he gave the foul, but I haven’t seen the replay."
Foxes manager Steve Cooper also said: "I don’t want to make the headlines around referees, because I’m trying to take responsibility for a team trying to do better in the Premier League, but it’s a clear foul on Jamie Vardy for the first goal and the left-back has to get sent off for a second yellow.
"There’s so much more we could say. The whole game knows, but I’m not going down that road today. We were very disappointed with a foul not being given on Vards for the first goal. And although we don’t come into games trying to get players sent off, why he hasn’t sent off Calafiori is a little bit beyond belief."