Football fans watching the FIFA World Cup matches are left to guess with little confidence if all the decisions taken after VAR review are correct ones.

Joining the list of some debatable decisions under VAR is the one involving Japan’s match-winning goal against Spain, which took the Samurai Blue to the knockout stage and kicked out four-time champions Germany out of the tournament.

In the Group E match, Japan defeated Spain 2-1 to top the group and qualify for the last 16 stage along with La Roja. Costa Rica which defeated Japan but lost to Spain and Germany, the other team from the group to be eliminated. Germany crashed out of the World Cup in the group stage despite a 4-2 win over Costa Rica on Thursday.

Japan’s path to the last 16 stage is now mired in controversy. The 51st minute goal which Ao Tanaka scored is the talking point on social media and debated hotly on television by soccer pundits and experts.

The goal was initially disallowed because the ball, a second before the goal, seemed to have crossed the goal line. The assistant’s flag went up for the ball being out of play indicating that Kaoru Mitoma, who cut the ball back into play, had dragged it into the paying area much after the ball had crossed the goal-line,

But the video assistant referee (VAR), after reviewing the play, overturned the call on the field because, although replays and still photos both appeared to show the ball crossing the line, it didn’t – at least not fully, apparently.

For the VAR, Fernando Guerrero of Mexico, to overturn the decision of the assistant, he has to have definitive evidence that part of the ball is on the line. Importantly, this isn’t just about the ball touching the ground. The curvature overhanging the line also counts, even if a very small part of the ball is doing so.

It’s a remarkable VAR decision to go against the on-field call. Fans have not been able to see any clear proof that the ball was touching the line when Mitoma cut it back to Tanaka.

But there is a confusion among fans as some camera angles suggest part of the ball might have crossed the line and there is no definitive evidence that Mitoma kept the ball in play.

It may be that subsequent pictures are eventually released, perhaps from the VAR-only cameras within the goal, but right now fans are being left to guess with little confidence this decision was correct.

On a night of high drama in Qatar, Germany and Spain both took early leads in results which would have put Germany through.

But it all changed in the second half with Japan scoring two quick goals against the Spanish, including the debatable second from Tanaka.

The officials originally ruled it out but the video assistant decided not all of the ball had gone out of play despite some replays suggesting it had.

If Japan had drawn 1-1 and not won, Germany would have gone through on goal difference.

Around the same time, Costa Rica also equalized against the Germans, who then hit the post three times before Juan Vargas put the Central Americans ahead.

That would have put Costa Rica through at the expense of Spain, but substitute Kai Havertz scored twice and Niclas Fullkrug got another.

It is the second World Cup in a row where four-times champions Germany have been eliminated in the group stage.

“For me personally this is an absolute catastrophe,” Germany forward Thomas Muller said.

“If this was my last game, I want to say a few words to our fans who have supported me for years. I have always tried to leave my heart on the field,” suggesting that he might retire from international football.

The game was also historic as it was the first men’s World Cup game to be refereed by a female – Frenchwoman Stephanie Frappart.

Storied Germany are the biggest casualties of the competition so far, with second-ranked Belgium also going out earlier on Thursday.

Coach Hansi Flick took over from 2014 World Cup-winning coach Joachim last year after a disappointing last-16 exit at the Euros.

Flick made a great start, winning his first eight games in charge but results in the Nations League then dropped off.

They began their Qatar campaign with a shock 2-1 defeat by Japan but fought well in the 1-1 draw with Spain.