The main flashpoint of the game saw Leicester striker Vardy dismissed for a two-footed challenge on Stoke forward Diouf.
England's Football Association will study referee Craig Pawson's report before determining whether to take punitive action against Leicester City following their eventful 2-2 draw at Stoke City.
The main flashpoint of Saturday's Premier League game saw Leicester striker Jamie Vardy dismissed in the 28th minute by Pawson for a two-footed challenge on Stoke forward Mame Biram Diouf.
Pawson was criticised for not dismissing Manchester United's Marcos Rojo for a similar foul against Crystal Palace in mid-week and he was confronted by Leicester manager Claudio Ranieri at half-time.
"I don't know. I don't want to speak about this. Every match is different," Ranieri said when asked about Pawson's performance in the wake of his failure to dismiss Rojo.
"Every decision could be different. We must respect the referee every time."
In the final seven minutes of the half, Stoke scored twice and Pawson booked five Leicester players.
It prompted stormy scenes at half-time, when Ranieri and his players confronted the official, who, in turn, appeared to have objects thrown at him by visiting supporters as he left the field.
Asked what he had said to Pawson, the usually mild-mannered Ranieri replied: "I said nothing to him at half-time. I just wanted to show to our fans, to my players that I was there. There was nothing wrong.
"I just said to our fans, 'Keep going, stay with us, we need your support.'"
For their total of six bookings, in addition to Vardy's red card, Leicester can expect an automatic FA fine, triggered when a team collects six or more cautions.
But Pawson's report will be studied closely by the authorities this week before they decide whether further action is warranted.
Ranieri was pulled away from a growing melee around Pawson at half-time by his goalkeeper Kasper Schmeichel and then appeared to point provocatively at the official as he left the field.
He insisted, however, that there was no sinister intent.
"No, I was pointing to the pitch," said Ranieri, whose side slipped to 15th place. "I was saying, 'Come on, it's important, support us on the pitch.'"
Ranieri also professed ignorance of objects being thrown at Pawson by his team's supporters.
"I didn't see them," said the Italian. "Of course, I would be disappointed (if they had)."
Former elite referee Howard Webb added to the controversy by saying that, following the Rojo incident, Pawson should not be allowed to officiate the forthcoming Liverpool-Manchester City clash.
"He's been given, on New Year's Eve, Liverpool against Manchester City. I don't think he should be on that game, no, not after the performance he gave on Wednesday night," said Webb, commenting on television.
"We're accountable, we make mistakes, we affect the results of games and we pay the price."
Stoke took a 2-0 lead into half-time courtesy of Bojan Krkic's 39th-minute penalty and a stoppage-time tap-in by Joe Allen.
But Leicester substitutes Demarai Gray and Leonardo Ulloa combined to reduce the arrears with 16 minutes remaining before Christian Fuchs set up Daniel Amartey to head in an 88th-minute equaliser.
Concerning Vardy's sending off, Ranieri pleaded his player's case and claimed that a challenge with Glen Johnson, immediately prior to his foul on Diouf, was a contributory factor.
It was a version of events with which Stoke manager Mark Hughes found little grounds for agreement.
"People are trying to say he (Vardy) was pushed and that was the reason he jumped in two feet off the ground," he said.
"I've seen the incident and it looked to me like he had two straight legs, he was off the ground and out of control.
"I can understand, there have been a couple of incidents where players have done similar and got away with a yellow card. They were deemed to be wrong, so this time the referee got it right."