Massey-Ellis is a highly respected referee in the sport. After remonstrating with the match official, Aguero foolishly reached out and grabbed her shoulder.
His actions were widely criticised, with many pointing out that he would be far less likely to treat a male assistant referee in the same way. Any physical contact with match officials by a player should result in a yellow or red card, depending on its' severity.
Manchester City manager Pep Guardiola was asked about the interaction between Aguero and Massey-Ellis after the match.
Sergio is the nicest person I ever met in my life. "Look for problems in other situations, not in this one", Guardiola said, according to BBC Sport.
The Argentine was contesting a throw-in near the end of a first half that City edged, and were leading 1-0.
"It was hard but we have won 1-0 and Ederson again was incredibly active like he was against Leeds", Guardiola said of his team's first league triumph at the Etihad this campaign.
Manchester City were looking to return to winning ways against an Arsenal team that had won three of their opening four Premier League games.