Robbie Neilson was furious after referee Willie Collum blanked his request to discuss two key decisions in Hearts' 4-0 William Hill Scottish Cup fourth-round defeat by Celtic at Tynecastle.

The Gorgie head coach was unhappy at skipper Morgaro Gomis' sending off in the eighth minute for his challenge on his Hoops counterpart Scott Brown.

Neilson was even angrier about Collum's decision to award the visitors a penalty early in the second-half when John Guidetti went to ground without any apparent contact from Jambos defender Brad McKay.

The Swedish striker scored from the spot to add to defender Virgil van Dijk's first-half strike and further goals from Anthony Stokes and Van Dijk again eased Celtic into the next round.

Asked if he tried to speak to Collum after the game, Neilson replied: "I tried to, he wasn't speaking to me.

"Some of them do, some of them don't. I don't know what the rules are, they change all the time.

"I've watched both incidents. I'm disappointed on the outcome of both.

"Everyone knows what the outcome of those decisions should have been but the one man who makes the decision didn't see it like everyone else.

"We were in a game last week where two (Rangers) players were booked for tackles that were far worse than Morgaro's tackle.

"Morgaro goes in and wins the ball and the referee decides it's a sending-off.

"We can't really argue against it because they always have things they can say - it's reckless, or at pace - but for me the second one, the penalty, is the real changer in the game.

"I am more annoyed at that but I'm also more annoyed that you can't speak to them.

"If somebody makes a mistake I would rather they just came and said 'look, I did it' and we could move on."

Asked if he thought Guidetti dived, Neilson replied: "The fact you are asking me the question probably answers your own question, doesn't it?

"I'm not going to try to get players sent-off or booked retrospectively. Everyone else will make decisions on that.

"We can only focus on ourselves and from my point of view it was the wrong decision."

Celtic boss Ronny Deila had not looked again at the sending off or the penalty by the time he came into the media room for his post-match press conference.

He said: I haven't spoken to him (John), but from my position it looked like a penalty.

"I think we had control of the game at that point. The red card was more important than the penalty.

"It's hard for me to say if it was a red card, but it was good that we maintained our tempo.

"We had good pressing and got the four goals which made the victory comfortable.

After another fine performance by Van Dijk, who would have had a hat-trick if he had not missed a first-half sitter, Deila expects there to be interest from England in the Dutchman when the January transfer window opens.

However, the Norwegian does not want him to move to an "average Premier League team".

He said: "I really hope he can stay here and that we can keep him. That is the priority.

"If he is going, I hope it is to the biggest clubs and not an average Premier League team.

"He has everything you need to do it at that [top-four club] level.

"But I hope we can keep him to challenge for the four competitions and that would be good for him, too.

"He is our player and we have a long contract, so I really hope we can keep him."