Just a couple months ago there were multiple instances of planes nearly colliding on runways because of ATC errors. So yeah, it happens.
Again, the two options are either a mistake or intentional. So you either have to argue that the VAR knew the goal was called offside and, with dear knowledge, intentionally said check complete, or you have to accept it was a mistake.
The weird thing here is that Liverpool fans seem to think that by calling it a mistake, it minimizes what happened. It doesn’t. Mistakes can literally be deadly. That doesn’t make them any less of a mistake.
Anyway, I’m done having this conversation. Liverpool fans here have convinced themselves that a team derided as LiVARpool is somehow on the receiving end of a mass conspiracy because klopp maybe said something mean. It’s impossible to speak rationally with the delusional.