The Neptune swimmer was the only athlete to go under the two-minute mark in the men’s 200m backstroke, clocking 1min 58.39sec in Auckland.
It was just outside the qualifying time of 1min 58.07sec required for the world championships.
"Honestly thought I did it," Follows told commentators when reflecting on the qualifying time.
"Life’s been a little different in the last few months, but felt like I adapted really well.
"Definitely know I was faster than that leading into this, so pretty disappointed."
It is the same event where Follows lit up the national championships last year, and qualified for his first Olympics after years of grinding away.
He reflected it had been a challenging time returning after a pinnacle event.
"It’s a tough transition at the best of times.
"I got told that I was too old, that I wasn’t fast enough any more. It was kind of just head down, working full time and just trying the best I can.
"I’m still proud of what I put out there today."
Kiwi club swimmer Liam Rees won bronze in the men’s 17-18 200m backstroke in 2min 09.47sec.
Fellow Kiwi swimmer Alfie Weatherston-Harvey — who won gold in the men’s 17-18 1500m freestyle and bronze in the men’s on Wednesday — finished seventh in 2min 10.98sec.
Alexandra’s Caleb Ludlow was the fourth New Zealander home in the men’s 17-18 50m breaststroke final in 31.15sec.
New Zealand swimmer Kale Twist — who broke the Otago 50m freestyle record on Wednesday — finished eighth in the men’s 100m freestyle in 50.91sec.
Former Dunedin swimmer Erika Fairweather finished fourth in the women’s 100m freestyle in 55.59sec.
