Mikel Arteta complained bitterly that Ivan Toney’s equaliser for Brentford ought to have been disallowed for offside after Arsenal failed to bounce back from last Saturday’s defeat at Everton with a win. Toney’s goal followed a deep free-kick which he himself sent back across the Arsenal area before it was returned by the substitute Yoane Wissa, who was beyond the far post. Ethan Pinnock rose to nod through for Christian Nørgaard, who hooked back for Toney to score, but there was controversy when the VAR, Lee Mason, spotted that Pinnock was offside from the initial free-kick. Arteta felt that Pinnock had blocked Gabriel Magalhães and, as such, was interfering with play even though he did not touch the ball. Mason did not agree. There was also the suggestion that Nørgaard was offside before he made the assist but that did not appear to be proven. “I just looked back and it is offside,” Arteta said. “Have they explained why it wasn’t allowed? No. It is frustrating but they will probably give an explanation later in the week. Today we haven’t got one. “You have to apply certain principles in defending and you do that by sticking to the rules. Suddenly you change the rules and then you have to change your principles. So tell us before so then you don’t hold the [defensive] line that high. Because you’re always going to have an advantage if you get blocked. You cannot block if you are offside.” It was put to Arteta that Nørgaard had looked to be offside. It was not apparent to the fans inside the stadium that the lines were put on the screen by the VAR to check this. “I think so,” Arteta said. “But then I’m hoping the cameras and the visuals … maybe it looks like there were two actions. I don’t know. It’s too late, it’s fine. The goal was allowed and we dropped two points. With the second [possible offside], I don’t know because you have to see the line the way they see it with the cameras. It’s irrelevant. It’s gone.” Arteta claimed to have been happy with his team’s performance even though most onlookers felt Brentford, who are unbeaten in 10 Premier League games, were full value for the draw. “It was a really strong performance,” he said. “I think we had moments. They are a really tricky team to play against so credit to them. We did a lot in the game and we did the most difficult thing which is to score the goal. So after, to have what happened in the way it happened, is frustrating. You need to be excellent in everything you do in the matches and you need certain decisions to go in your favour as well.” The Brentford manager, Thomas Frank, said: “It’s insane that it’s possible for us with the second-lowest budget to be unbeaten and all 10 games have deserved wins or draws. It’s not like we’re crawling over the line. That’s maybe even more impressive.”