Throw in a bungled television match official review of what appeared to be a dangerous 10th-minute clean-out by the Warriors flanker Callum Gibbins on Munster’s Sammy Arnold when the score was 0-0 and you would have forgiven van Graan his apparent tetchiness during his post-match interview.

Normally graceful and open in defeat when facing the media, the South African answered the questions from a Premier Sports interviewer in curt, one-sentence answers although it is understood the Munster boss was surprised that had been the viewers’ perception of the interaction.

Regardless, van Graan had by Monday gained a full grasp of the fixes required this week ahead of the Ospreys clash in Cork and though sloppy errors in defence and attack cost Munster dearly, it was his team’s poor set-piece play in that first half that most exercised him.

We’ll have to sort our set-piece, it’s a big focus point for this week and then there’s a different flow to the game,” van Graan said.

“If you look at the first half, we conceded the penalties and got pinned in our 22. In the second half, they conceded penalties, they got pinned in their 22, we lost set-piece twice, five yards from the line and unfortunately, that was the difference.”

Adding to the frustration was the failure to properly review the 10th-minute ruck clear-out on Arnold which appeared to show Gibbins lead with, rather than attempt to wrap, an arm around the Munster centre.

Referee Ben Whitehouse asked his TMO Neil Paterson to check the incident as play continued but it was almost two minutes before Glasgow’s attacking phases were brought to a halt by a penalty against Munster’s Mike Sherry.

Whitehouse then called for a video review and while the incident was replayed once, neither referee nor TMO appeared to see it and instead reviewed two different and incident free rucks.

“We’re struggling here, to be honest,” Paterson admitted.

We’re going to have to play on if you can’t find it,” Whitehouse told his TMO, to which Paterson replied: “Yeah, I think you should go with it because we can’t, there’s nothing that we’ve got.” “So there’s no angles you can provide,” the referee concluded, before resuming play with a Glasgow penalty for Sherry’s offside offence.

When asked about the officiating on Monday, van Graan had no issue with Whitehouse’s refereeing and said he was satisfied with the feedback he received post-match from Guinness PRO14 elite referees manager Greg Garner.

I’ll put it to you this way, there were quite a few incidents in this game, we spoke to the referee’s manager as we do every single week, it’s important to keep that relationship going, he’s done very well in communicating back to us and they’ve been very consistent.

“The only thing that all coaches want is clarity, clarity regarding certain incidents and the TMO incident on Sam, the TMO couldn’t find it and I can’t do anything about that now.

“The communication has been constant, it’s very important for player welfare that we look at the right things and we play within the spirit of the game, I thought it was very well handled by Greg over the weekend.

“It’s obviously not the ref’s mistake, he can only see what’s on the screen. It is frustrating but I can’t do anything about it now. We’ll handle it afterwards through the right channels and I’m satisfied with the explanation that was given to me, we’ll move on from that.

“That being said, I’ll never blame a referee if we lose a game. It’s not nice, we need to be better and they’ve got such a difficult job making decisions. The only thing we want is clarity and consistency and a good game of rugby.”