Referee Mick Russell is set to be investigated after failing to send off Sheffield Wednesday’s Jeremy Helan despite showing him two yellow cards.
The Hertfordshire-based official booked the winger for a second time in the 26th minute of their 0-0 draw against Huddersfield, but failed to produce a red card.
On-loan from Manchester City, Helan was initially booked after nine minutes for diving in the penalty area, before receiving his second yellow for a foul on Huddersfield’s Adam Hammill.
Huddersfield boss Simon Grayson told BBC Sport: “He’s not done it deliberately, but you can’t make major mistakes like that. Something quite simple like that shouldn’t be happening in Championship football.
“I think he’s probably written the wrong number down in his book, which is staggering, I also think he should have been helped by his officials.
“I’m not going to say Wednesday going down to 10 men would have guaranteed us winning the game, but it would have certainly helped us.”