But they were stuck with it. There was no 'rescue'.
They couldn't whistle up a helicopter to lift the seven-tonne cat out of the water and fly it back to base. There was only one way home. So Ashby talked to his crewmates, telling them that the best way to go home was ... flat out.
"It was one of those times where you had to commit. We had no choice. There was a line in the sand and we had to cross it to get the boat back safely. It was definitely intense yachting," he says, "but it was great. It really worked out well."
It was a seminal moment for Team NZ. It took them from slightly hesitant newbies to a state of some assurance that they could handle the beast.
"It gave everyone confidence," recalled Ashby. "We were humming through those waves and everyone realised that the boat was solid and good and all we had to do was push hard and the boat would look after us. I told them that speed was our friend - and that rang true at the end of the day.
"It gave us a lot of confidence, not just in the boat but in the design team - and that's one of the things about being in Team NZ - I don't think I have ever worked so closely with a design team. That run taught us not only that the boat could be pushed hard and go quickly; it also told us that the safest way was the quickest way. That day really took us forward as a sailing team."
Speed is an ideal state of affairs for Ashby. He likes going fast. That's why he is a multi-hull sailor. Born in Melbourne, he moved out to Bendigo with his family and learned to sail - his mum was the sailor in the family - on a lake there. He laughs when you say he must be the only lake sailor in the America's Cup.
"Yeah, that's right - I'm not sure anyone else here learned to deal with shifting breezes and random waves. I really enjoy going fast. I love the high speed and the efficiency of these boats; for me, it's wonderful."
Last year, as part of his developmental work for Team NZ, Ashby paid from his own pocket to buy a Moth, the hydrofoiling dinghy which goes like stink and stands up on its foils - just as the AC72s are now doing.
"I lashed out and bought a boat and Peter Burling [the New Zealand Olympic silver medallist in the 49er skiff class and one of New Zealand's brightest yachting hopes for the future] had just got back from the London Games. He'd come down to the Viaduct, we'd chuck the boat in the water and train together."
It was useful experience, combining what they learned about foiling with the Moth, combined with old school multi-hull knowledge and their own background knowledge of foiling. That, and the 33-foot catamarans which Team NZ were also using to advance foiling skills, all went into the mix.
From that mix, plus their close work with the design team, came the ability to foil and foil quickly through manoeuvres which has seen ETNZ do so well so far at this Cup - and which shape as key elements in the Cup match against OTUSA.
Ask Ashby what is the difference between OTUSA and ETNZ and he talks about philosophy. This is the guy who coached non-multi-hull sailors to victory in the giant, 90-ft trimaran USA 17 when Oracle took the Cup off Alinghi in 2010.
"Our [ETNZ] philosophy has been that the sailing team develops skills in parallel with the design team. I really like that and I think it is a philosophy that has grown. We have worked really closely with the designers and the engineers and I think it has given us an edge.
"It's felt like a good connection right from the start. There has been a real feeling of teamwork and unity and it's grown as we learned to get the boat round the track quickly and safely.
"The Oracle philosophy was a little different - they sort of came up with the design and the sailors had to learn to deal with the boat and learn how to sail it best. There's quite a difference in those two approaches.
"The culture in Team NZ is really unbelievable. Our guys come together and bounce ideas round and there's no silly questions or stupid ideas. You'll say something one day and feel a bit stupid and then, a few days later, one of the design team will come up to you and say, 'You know, there might be something in that...'.
"I have really enjoyed that; we have been pioneers of a sort - and that's what I wanted; a new challenge."
Like everyone, Ashby isn't sure who is faster - ETNZ or OTUSA and he says Spithill and Barker are both driven, intensely competitive skippers at the top level of their sport. Both were eager and quick to learn, he says.
The 90-foot Oracle trimaran from 2010, with its 200-foot wingsail, was definitely the scarier beast, he says.
"It was all about managing things securely and safely. I said to all the guys that we had to push hard and push through to the next level. I think we did that but we pushed that big thing quite hard and it was scary sometimes.
"The AC72s are a breath of fresh air to sail and not be worried about breaking it."
Ashby relates his job on board as wing trimmer to that of a truck driver. Just as a truckie has to make dozens of little gear shifts, so Ashby controls the gearbox of Aotearoa, sometimes with subtle little adjustments to maximise the windspeed, sometimes with more pronounced adjustments.
The wing is set up differently upwind and downwind and must be used carefully with the forward sails, meaning loads of 'gear changes'. Watch the excellent on-board camera coverage in the Cup and you will see Barker, tactician Ray Davies, Ashby and forward trimmer James Dagg all constantly talking to manage the speed and angle of the boat. And we are about three weeks away (or possibly sooner) to discovering whether the little Aussie from a lake in Bendigo has played a key role in lifting the Cup. Again.
