"I went for the green in two, had a bit of a pull. It went in the water on the left side and I ended up making six, which I thought would have missed by a couple."
As he walked off the final green, he saw the cut mark for qualifying was at 16 under par. If he'd played safe on the last and made a par, he would have retained his ticket.
"I just didn't believe it. I was in shock. I went for something I didn't need to do. All my friends and family in New Zealand in the middle of the night knew exactly what was going on and I had no idea at the tournament.
"It was so frustrating. I played great but I was let down by the scoreboard or the lack of information available. I couldn't use the phone. That's against the rules."
There is a modicum of good news though.
By finishing 177th on the European Tour money list with 102,989 euros this year, Geary is still eligible under what's called "Category 22" to get between 10 and 12 starts on the 48-event European Tour schedule. But his low category status means he'll only have a place in an event if there are spaces to fill. Therefore he can't schedule his year with any certainty.
If he'd made a five on the last hole in Spain, he would have had over 20 starts from a higher category.
"I'm still shocked by it all. But I have to take the positive out of it. Hopefully it gets me fired up to do something good early on. It may all change in the first few weeks but at this stage it's pretty hard to cope with."
So much for Geary now depends on how he plays in the two events which are co-sanctioned on the European Tour and the Australasian Tour in February – the Vic Open and the Perth Super Sixes.
If he can get a decent placing in either of those, his ranking, and therefore his status, will improve considerably. This is golf's version of democracy. Play well and you get rewarded with a good pay day, then with more starts and the chance to make even more money. Play poorly and you're battling to keep afloat.
Geary knows all about the highs and lows of the professional game. He started playing for money in 2007 after a brilliant career as an amateur when he won countless tournaments and represented New Zealand at the highest level, in the Eisenhower Trophy.
But what had been tipped as a stellar life as a touring professional has often run face to face with the reality of just not making cuts.
He's played all over the world and he's won often. But just not at the absolute highest level. There've been three wins at the Carrus Tauranga Open on the Charles Tour, three wins in the PGA Tour China Series, the West Australian PGA and a win on the Canadian Tour.
But that breakthrough victory on a major tour, like in Europe or even on the second tier Web.com Tour has eluded him.
But now at age 34, he seems as enthusiastic about the game and his future prospects as ever.
Much of that can be attributed to a new coach he took on in March last year, Ian Godleman, who was able to be at some of the events Geary played in.
Although he still works with Auckland based Jamie Kupa, Godleman's presence at European events has been influential.
"Just having someone out there with you is a big help," he says.
"All the top guys have their own physios and coaches, a whole team. It just makes you that little bit sharper."
Godleman's influence is easy to see in Geary's 2018 results. He missed the cut in every event he played from January to mid April. Then in his next six starts through to early June, he made the cut five times and had his first top 10 finish on the European Tour, in the Belgian Knockout.
Although he never placed as high again for the rest of the year there were signs of more consistency coming into his game. He made four cuts in succession towards the end of the season proper in September, and then won at the second stage of the Qualifying School before the final grind.
There were moments of brilliance during this time as well, periods that his followers from the amateur days will remember so well when he could reel off birdie after birdie in spectacular fashion.
In the event called Made in Denmark in the first week of September, Geary had seven birdies in eight holes during the first round. He finished with 66 that day, but faded in the next three rounds to eventually finish in a tie for 49th.
But it's those sorts of days which have him full of optimism about 2019.
"The last half of the year was really good. I had some great progress in the long game. But my putter was really cold the whole year really. People who know me will find that pretty surprising."
The issue will be his schedule.
"I don't have the luxury of picking and choosing events. You just have to show up when you may get in, and that's why there's not that many guys keep their card after going through Q school."
Since he's been back from the horror of the experience in Spain, Geary has continued to show consistent form in local tournaments. He shot 67 at the Mount Pro-Am and then returned 65-71 in the Michael Hill Pro-Am at The Hills for third place.
His competitive year is likely to start with some more New Zealand Pro-Ams in January, although a schedule hasn't been posted yet.
But the first two weeks in February will be key. He has no status for the rich swing of three European Tour events through the Gulf States but the new Vic Open in Geelong, with A$1.5 million on the line, gives him a great opportunity to not only get some dollars in the bank, but improve his status as well.
"The game's all there which is encouraging. The way I'm swinging it I'm pretty confident next year I can do some good stuff early on.
"The hardest part will be getting the starts."