In what circumstances can VAR invoke a legal challenge?

Bournemouth considering it apparently, a recent shocker of an evening which ended with the VAR people admitting their errors had affected 3 PL results, I think this was Villa v Sheff Utd.

Their equipment was faulty (apparently) which should be their responsibility.

I don't think they can win..

Other teams could say but if this and that happened we would have done this.

Also who knows if Villa would have lost that game.

Exactly. If it does happen then I want us to go after Clattenburg for cheating us out of the cup in 2016.

Exactly he has admitted his errors but still laughs at his record when reffing Palace games

Correct. The problem is no-one knows how the game would have finished if the goal had been awarded. The game would have restarted from the centre spot, instead of carrying on and would have followed a different course. IMHO Bournemouth will be wasting money by taking legal action on this one.

According to Hawkeye they had 7 cameras and by bad luck and for the first ever a player was blocking the view from each of them hence the technology failure.

In human terms it is no different to the referee and linesman saying they didn't spot something because their view was obstructed. I believe the rules allow for mistakes to be made it's only if you can show that the referee was bribed or the technology sabotaged that you would have a case.

Regarding the specific incident the solution lies with more technology in this case VAR. The VAR camera's clearly showed what happened so the VAR officials should have used their common-sense and alerted the referee that something was wrong and to go look at the monitor. Hopefully they have now been instructed to intervene which after all is the point of VAR a clear and obvious error.

One more point