Mikel Arteta and Bukayo Saka could not hide their frustration after seeing Joao Pedro escape punishment for kicking the ball out.
The Brighton star chased the ball down 18 minutes into the first half of the 1-1 draw but was unable to stop it from going out of bounds against the Arsenal underground shelter.
In frustration, Brazil kicked the ball away, prompting Arteta and Saka to wave their hands in protest.
Although it was an isolated incident at the time, Pedro's behavior became much more apparent afterwards. Declan Rice sent off.
Having been booked for a late challenge in the first half, the Gunners star appeared to kick the ball away during an altercation with Joel Veltman.
Veltman then attempted a quick free-kick but the effort was intercepted by Rice, causing the Arsenal player to fall to the ground.
But while fans at the Emirates Stadium were hoping for the Brighton man to be punished, it was Rice who was sent off for delaying the restart.
Arsenal were furious with the decision, especially given what Pedro and Brighton had achieved earlier in the half.
Asked if he had an explanation for Rice's red card, Arteta said: “No explanation, as usual.”
He continued: “If (a yellow for delaying the restart) happens throughout the game consistently, then it's fine.
“But it wasn't like that. In the first half there were several occasions when they kicked the ball and nothing happened.
“So it's an inconsistency, especially since it's in an area that's not critical.
“And besides, you made the decision, you have to give a red card too.
“We had to play with 10, so they should have to play with 10 because then it would be a red card for Veltman.”
Saka echoed those sentiments and criticised referee Chris Kavanagh's lack of consistency when the video of Pedro kicking the ball went viral.
“We just want consistency. João Pedro kicked the ball into the middle of the field in the first half and got nothing in return.
“Dec received the slightest touch and was sent off.”
The sending off overshadowed the Premier League clash in north London after Kai Havertz had given Arsenal the lead.
That goal was cancelled out by Pedro, who equalised in the second half to deny Arsenal all three points.