The 31-year-old Scotsman found himself on the canvas for the first time in his professional career after Catterall caught him by surprise in the eighth round.
Taylor, the betting favourite, was more surprised than hurt by the fast left hook.
The three judges Howard Foster, Victor Loughlin and Ian John Lewis all scored the fight differently – 2-1 for Taylor.
Foster had it 113-112 for Catterall, Loughlin the other way round, while Lewis had Taylor winning comfortably, 114-111.
It was the 19th straight victory for Taylor, who turned pro shortly after winning gold at the Commonwealth Games in 2014.
Speaking exclusively to GIVEMESPORT, DuBoef said: “I mean I think the knockdown was one thing, but I felt he started coming on in the late rounds, and in the back half of the fight I thought he started just getting into his gameplan.
“He started not letting him tie him up so much, being the aggressor, pushing him back, and that’s when he really did start getting back into it.
“Josh showed his champion mentality coming back in the way that he did. It was very impressive. But he did dig a hole for himself.
“It was a horrible, sloppy fight to score. You had points taken here, points taken there. It was a very difficult fight to score.
“But I think at the end of the day, he got it done.”
After the fight, Taylor made it clear that he will move up to welterweight to challenge either Terence Crawford or Errol Spence Jr.
But DuBoef refused to be drawn on questions about his future as he insisted they still have plenty to work out before making a decision.
He added: “I feel like it’s like we’re served up all these questions that we have to respond to in two seconds, right?
“It’s like, is he going to fight Kell Brook, is he going to fight Terence Crawford, is he going to fight Shawn Porter?
“I mean, it’s so difficult. It’s not like a ping pong match where you have to return a ball right away. I think you have to sit down, right?
“Ben and him have enough conversations and they have to say, listen, we’re not staying at 140, we’re definitely going up to 147, we want some fun thing maybe in between until we get a title fight, I don’t know, so we’ll have those conversations.”
Despite the controversy, DuBoef believes it was an overwhelming success overall.
He continued: “You know, the atmosphere was fantastic.
“Coming to Scotland for my first time was amazing. You know, we do fights all over the world, and this was one on my bucket list, right? What a way to start.
“Great atmosphere, people cheering, local town guy. You felt like this was as big as a massive football match. People were all there. So it was terrific.
“We pride ourselves on creating that in arena experience and doing a lot of things that get the juices flowing, you know, like we’re all here to present a really good show, right?
“You can’t do anything about the results of the fight but to hear the fans roaring and seeing their local guy come in and hearing his name announced, that’s what makes it so sweet and special.”