VERN COTTER last night sidestepped criticism of the referee after a controversial defeat to Wales at Murrayfield.

The Scots came up just short as Wales edged a titanic RBS 6 Nations match 26-23 but the contest was packed with questionable decisions, most notably when Scotland centre Mark Bennett was denied a try and when the referee, Glen Jackson, blew for time up after Jon Welsh scored a try from the home side after 79 minutes and 20 seconds.

Jackson, the referee who was coached as a player by Cotter at Bay of Plenty, decided there was no time left for a kick-off, drawing roars of anger from the crowd. Earlier he had penalised Sam Hidalgo-Clyne for a knock-on after he was felled by a high tackle as the ball ran on for Bennett to score.

Cotter was careful in comments about the officials, saying: "We're in constant communication with them. We'll try and send something through that will help them, perhaps."

There was laughter at the New Zealander's dry delivery of the line but he seemed less than pleased with the officiating, adding that he believed that the referee should have gone for a video review of a possible try from his captain, Greig Laidlaw.

Jackson also yellow carded one player from each side: Finn Russell of Scotland and Jonathan Davies of Wales.

Cotter, too, raised the possibility that constant Welsh infringement in the final quarter could have been penalised by another yellow card.

But he added: "There are a lot of things we don't have control of. I don't want to lose a lot of energy talking about it because it isn't going to change the result."

However, Cotter, presiding over Scotland's second defeat in the tournament, said: "What we can do is take some positive things out of the game and things we have improved from Paris and for me that is encouraging."

He was, though, not blind to the errors committed by his side in the match. Scotland lacked composure at times and amassed a penalty count of 13.

He said: "This game illustrates areas we need to work on. Somebody will look at the ref display or decisions made on the paddock. We have things to sort out and perhaps they will have as well."

He said of his side's penalty count: I mean to have a look at the penalties against us, how many were 50/50s how many were preventable, non-negotiable. As a group we have to have a look at how we approach rucks or how we do our homework on refs so we adapt as best as possible."

His captain was quietly critical over the refereeing in the final quarter, saying: "We finished very strongly in the end there and as Vern touched on there were six penalties in the 22. I was disappointed not to get anything out of that."

Of the decision to end play without a kick-off after the try, Laidlaw said: "The ref will have to look at that. From where I was sitting there was time to take the kick. Whether we would go on to score was a different matter we will never know that."

He added: "It's very frustrating. We talked about small margins after the result out in Paris. As Vern said, we've got to keep working and improve our game. This group of players is becoming a strong team. I really believe we're not far away, and we need to keep believing.

"We've got a massive game against Italy at home, and all that matters now is that we turn up in that game and get a positive result."

Sam Warburton, the Wales captain, and Warren Gatland, the head coach, both praised Scotland's performance.

"I think Vern's brought a bit of that Kiwi mentality. If they're not going to win they're going to be a tough team to beat," said Gatland.

Warburton said of the decision to end the match straight after the conversion: "We were ready for that kick off. I would have backed ourselves to keep them out. I wasn't going to complain when they blew the final whistle."

He said of Scotland: "I've played against them about five times now and that's the toughest match I've been involved in. Credit to Scotland, they impressed me."