A losing bonus point after the Bulls’ Keegan Johannes had kicked the winning points for the the South Africans, who remain on course for a home play-off draw at the end of May, was scant consolation for Munster’s interim head coach. Yet it was the confusion surrounding injuries to both starting tighthead prop Oli Jager on 14 minutes and then his replacement Stephen Archer 38 minutes later that left Costello’s team unfairly short-handed between the 52nd and 65th minutes. It also left home supporters wondering what might have been had their side been able to remain at 15 men throughout the game. Archer had replaced Jager on 14 minutes after the starting prop was removed for a Head Injury Assessment, from which he did not return. When Archer was then injured in the second half, Jager’s HIA was not taken into account and with no recognised tighthead left on the Munster bench, referee Andrea Piardi called for uncontested scrums and ordered an extra forward off, back-rower Alex Kendellen. It took 13 minutes of pitchside negotiations for Munster to make their protests stick and for Kendellen to return to the game, and left referee Piardi having to explain the situation to both captains, Tadhg Beirne and Ruan Nortje. Remarkably, the Italian official admitted to them that there were “too many rules” in rugby and implied that because the score had remained 13-13 during Kendellen’s absence that the situation was okay. Piardi’s full explanation to the skippers relayed to a wider audience by the referee’s microphone, was as follows: “Okay, some problem from the outside and I will try to explain it. There are too many rules in this game. So, the first injury (Jager) by Munster was for HIA. So, you shouldn’t go 14 (players). So now we play like this, we stay with the 13-13 (scoreline at the time), which is fine. “But now I am asking another player (Kendellen) to come in, okay, and we play 15 against 15 because the first injury was HIA. Okay? Now, we still have uncontested scrums for 15 minutes.” Asked for his reaction to the bizarre events, Costello said: “We looked for clarification and unfortunately the information we got was we were down to 14 and then it got pretty confusing. A lot of people got involved. “You can’t stop the game obviously. You probably would have seen everything that was going on on the sideline. Yeah, look, it’s one of those situations, it’s disappointing, but it isn’t the reason we lost the game. But yeah, it’s far from ideal. “I suppose what probably made it difficult was that Oli, the first substitution was for a HIA, the second one (Archer) was for an injury and that HIA should have ensured we stayed at 15. “But look, it took 13 or 14 minutes before it got overturned and that’s something that we have got to look into. “But that isn’t the reason we lost the game. There were too many elements in our performance that weren’t where we expect them to be, and we have to take that on the chin.” As to those elements that fed into a critical Munster defeat, following on from the previous Saturday’s Champions Cup quarter-final exit to Bordeaux, the interim boss added: “There were probably quite a few issues. I suppose it was such an emotional high over the last few weeks and that was always going to be the challenge and there were some aspects of our game that were a little bit flat. “We use things like ‘bigs’ and ‘bounces’ to measure our energy and we were just a few per cent off on a lot of things. And they are a physical side, tough conditions, and I think yeah, it was probably spread across a few areas of our game. “It’s one of those ones where you’re not really sure straight away afterwards, that you can’t put your finger on, but we have 24 hours to review it. We are back in again on Monday with a six-day turnaround to an absolutely must-win game next Friday. Simple as that.” Munster travel to fellow play-off contenders Cardiff next and will be hoping to have some more players back after short-term injuries sustained against Bordeaux-Begles. Calvin Nash, Gavin Coombes, John Hodnett and Diarmuid Barron all missed the Bulls game while Craig Casey (illness) and Peter O’Mahony (tight hamstring) were withdrawn at the end of the pre-game warm-up at Thomond Park. “We knew Craig was sick,” Costello said. “He looked like he had recovered and Pete had a tight hamstring. They got through the majority of the warm-up but just came up short near the end. “We had contingencies. We have to be able to adapt, so we had a very specific plan for that, if one went or if two went. So, yeah, it’s not ideal but we have to be better than that. “It’s probably more around the characters that we lost. The two of them are so influential. There’s such leadership from the two of them. The boys (Conor Murray and Jack O’Donoghue) came on and did a fine job but we have to adapt better.”