Arteta's side looked as though they had suffered a huge blow in the Premier League title race when Wilson slammed home in stoppage-time after Gunners keeper David Raya dropped the ball.
But Kavanagh eventually disallowed the goal for a foul by Pablo on Raya after being advised by the VAR officials to consult the pitch-side monitor.
West Ham were furious with the decision but Arteta claimed justice was done.
"Today I have to congratulate them. They showed a lot of courage and bravery to stand out and give the opportunity to the referee to have a look at the action," he said.
"When you see the picture, there is no question that it is a clear foul. They were very brave. The action deserved that.
"In my opinion, it is very clear. They are the rules and we ask for consistency.
"But today I realised for the referees to be in that position and make that call and change the course of one the two teams, what a responsibility. What a big call."
The controversial decision left Arsenal on the brink of winning the title for the first time in 22 years.
They sit five points clear of second-placed Manchester City, who host Crystal Palace for their game in hand on Wednesday.
The north London club will be crowned champions if they beat Burnley at home on May 18 and win at Palace on May 24.
'Beauty of the Premier League'
"I am going to certainly remember this day. It was a rollercoaster of emotions," Arteta said.
"We knew it was going to be tough day; West Ham are fighting for their lives and we are trying to win the Premier League.
"So much at stake. We started the game so well and had three big chances. Then the injury of Ben White, we had to make a change and adapt, we had to make difficult decisions.
"We threw everything we had to try and win it. We were rewarded for that courage."
With the long-awaited title now in touching distance, Arteta singled out Raya and Martin Odegaard for their priceless contributions.
Raya made a brilliant save with his foot to keep out Mateus Fernandes' close-range effort when the score was still 0-0.
Odegaard, used sparingly by Arteta in recent weeks, came off the bench to provide the assist for Trossard's winner with a clever run and pass.
"If you want the chance to major trophies, you need moments and actions and the individuals creating those magic moments and David certainly - like Martin Odegaard - created a moment to win us the game," said Arteta, who has also led Arsenal to the Champions League final against Paris Saint-Germain on May 30.
"Martin made an incredible action to win us the game after David's save. In the end, this is the beauty of the Premier League."
Asked how he felt about Arsenal being two games from title glory, Arteta added: "Now we leave and enjoy what we have done today, because as I said it has been an incredible week.
"Those players, the way they are standing in front of the opportunity and showing resilience, it is remarkable."