VAR audio has been released.
https://www.premierleague.com/news/3...?sf269410963=1
it's just pure incompetence. They draw the line and immediately see it's onside, but they apparently missed that the on-field decision was offside. And they understand the error they made within a couple of seconds, but since the game has already re-started, it's too late. Just a rushed process and bad communication.