Red Bull Formula 1 team boss Christian Horner says the pitstop delay that cost Daniel Ricciardo Monaco Grand Prix victory was a misunderstanding rooted in the track's unusual garage arrangements.
The Monaco pitlane is more cramped than other circuits', and the teams' usual pitwall set-up is located above the garages.
Red Bull was not ready with the tyres when Ricciardo came in from the race lead for slicks, and the resultant delay as a set of super-softs was brought out meant he emerged just behind eventual winner Lewis Hamilton.
Horner said a set of super-softs had been requested without the management knowing that the crew had softs ready and would not have time to get the super-softs before Ricciardo arrived.
"We saw Hamilton the lap earlier go onto the ultra-soft tyre, which we felt was quite marginal to go to the end of the race," Horner explained.
"So we elected to put Daniel onto one step harder tyre.
"Basically there was a miscommunication as to what tyres were in the garage at what time.
"The pitwall is upstairs, obviously the garage is downstairs, tyres are on heat both in the garage and behind the garage. Unfortunately the set of tyres that were called for weren't readily to hand and were at the back of the garage.
"There was a scramble, with the mechanics originally having the soft tyre ready."
While stressing the misunderstanding would probably not have happened with a standard garage layout, Horner said Red Bull could not blame the Monaco pits for its mistake.
"Not making excuses because there are none, but obviously with the tightness of the garages here, it's very tight to have extreme wets, intermediates and three different types of slicks for both cars in the garage at the same time," he said.
"It's a communication error that has happened with 30 seconds' notice that on a normal working day would have been no issue at all.
"It's a challenge in Monaco for all the teams when you're sitting upstairs.
"The race engineers don't have sight of what tyres are in the garage.
"But we need to understand and do a full analysis of how this happened and ensure it doesn't happen again."
Ricciardo dominated the early stages from pole but initially fell behind Hamilton when he stopped to change from wets to intermediates while the champion chose to stay out and wait for the track to dry fully so he could go straight to slicks.
Though Ricciardo then ran one lap longer than Hamilton before changing to slicks, he was on course to reclaim the lead and came out only marginally behind the Mercedes even with his pitstop having taken nine seconds longer.
"Even despite that delay, they came out alongside each other, showing how quick Daniel's in-lap had been and how slow Lewis's out-lap had been," Horner said.
"All we can do is apologise to Daniel that we haven't given him good enough service today."