Gallagher has acknowledged that a free kick should not have been given for Davinson Sanchez's challenge on Alexis Sanchez, but Spurs were further incensed after Shkodran Mustafi appeared to score from an offside position from the resulting set piece.
However, Gallagher has suggested that the small margin between Mustafi and Spurs' last man should result in the decision being 'accepted by everyone'.
Gallagher told Sky Sports News: "Clinically, the VAR would say it is offside but what you would say it is a decision which everyone would accept. It's so tight.
"Throughout the season, every team has been a victim of this and different teams have been successful with it. It has balanced out. It's so marginal to the naked eye that it is just a decision that you have to accept".
Arsenal went on to win the game at the Emirates Stadium by a 2-0 scoreline.