Howard Webb has commended the process that led to West Ham’s equaliser against Arsenal on Sunday being overturned, describing Pablo’s foul on the goalkeeper David Raya as “clear and obvious”.

In what has been described as the most consequential decision in VAR history, the referee Chris Kavanagh chose to rule out ­Callum Wilson’s late goal at the ­London ­Stadium, ­handing Arsenal an advantage in the title race. While Webb, the chief officer of Professional Game Match Officials (PGMO), did not blame the official for missing the initial incident he argued it was inevitable that VAR “would have to get involved”.

Speaking on Match Officials Mic’d Up, Webb said PGMO had ­specifically warned players at the beginning of the season against making the type of foul performed by Pablo on Raya. “Is it a foul on the ­goalkeeper? ­Categorically, yes,” he said. “We’ve said all season, ­including in ­pre-season briefings with the ­players, that if a ­goalkeeper is impeded by an opponent grabbing or holding their arms and therefore can’t do their job, they’ll be ­penalised. We’re not just talking about contact with goalkeepers, we’re talking about a specific type of contact when the goalkeeper’s arms or hands are being interfered with, stopping them doing their job.

“When you see the best angle on this, you’ll see that that’s what ­happens from Pablo. And on the video, it’s clear and it’s obvious, and it happens early. Even though it’s not clear and obvious to the ­referee because he’s got a huge group of ­players in a penalty area, and it’s ­difficult to see, when the VAR sees this, of course, they have to get involved.”

Webb said that officials at Stockley Park, in this case the VAR, Darren England, and assistant VAR, Akil Howson, had been aware of the significance of the moment when making their decision and had been “diligent” in their work. The check process lasted more than four minutes in total. “It takes a bit of time because they’re going through a process pretty diligently because they really respect the game, and they’re aware, of course, of the size of this situation, the importance of this situation,” Webb said.

“We have to take our time to get it right in this really important situation. We did, and you’ll see this offence being identified, and rightly, the VAR recommended the referee look at the screen and looked at everything as well, not just that individual situation. They were diligent. They looked at the entire piece and were able to identify the offence that needed penalising.”