Three red cards - are referees getting tough at this World Cup?

It looked like a coming together off the ball, but the referee was sent to the pitchside screen by the video assistant referee (VAR), Colombia's Nicolas Gallo.

As Sampaio was shown the replays at the monitor it was difficult to make out what had happened.

Was there really a hand to the head? And if so, was it accidental or did he swing the arm?

When assessing violent conduct, the VARs are told to look for a clenched fist as a sign of aggression. This does not have to be present, but it is an indicator.

Zwane appeared to connect with an open hand to the side of Alvarado's head, not with a closed hand.

It looks exceptionally harsh, and not the kind of clear and obvious decision VAR as introduced for.

Or maybe this is exactly the kind of thing Collina had told his referees and VARs to look out for, falling into the category of poor player behaviour.

Collina has brought in red cards for players who cover their mouths in confrontations, and those who leave the field in protest at a decision. He also wants goals disallowed for blocking on set-pieces.

Perhaps the actions of Zwane fall into this sort of category, a way for Collina to try to reduce the dark arts within the game.

Let's not panic about the referees just yet

The third red card, again for Dogso, seemed controversial initially.

Khuliso Mudau broke towards the area and looked to skip past Montes, but the South African was stopped in his tracks by a rash tackle.

Mudau was in a slightly wide position so a yellow card seemed the most likely outcome. Sampaio produced the red. Surely the VAR would step in again?

On second viewing it seemed very likely that Mudau's next touch would be to control the ball inside the area. There was no covering defender close.

Mudau would probably have had one touch, and then a shot. The VAR was not likely to get involved and tell the referee he had made a clear and obvious error.

An incident from the Premier League last season is a good comparison. It came in Crystal Palace's 3-3 draw with Bournemouth in October.

Marcos Senesi brought down Ismaila Sarr, with the Palace striker moving into a similar position to Mudau.

Referee Jarred Gillett produced the yellow card, but the VAR sent him to the screen to upgrade it to a red.

Gillett rejected the review, but the Premier League's Key Match Incidents Panel voted that he was wrong. It should have been a red card.

Maybe it provides an indication that Sampaio was right. His decision was certainly supportable.

Collina is not the kind of administrator to launch some kind of crackdown on Dogso. He made his aims clear before the World Cup started.

It would be easy to say this World Cup is about to be blighted by referees throwing around red cards.

There is a danger we fall into a trap, whereas this game may well prove just to be an outlier. A statistical anomaly across a 104-game tournament.

The two on-field red cards probably are, on balance, both correct decisions.

Let's not panic about the referees just yet.