Considered pioneers of the groove-led thrash sound, New Orleans heroes Exhorder were adored by Pantera singer Phil Anselmo.
And when Pantera moved from their original glam metal sound to the groove metal of 1990's Cowboys From Hell and the style that made them one of the biggest bands on earth, some people pointed out similarities with what Exhorder were doing at the time.
Harsher critics have called it a straight-up rip-off.
Thomas says his band may have done some things before Pantera followed in their path, but he doesn't have a problem with it.
He tells Heavy Culture: "Pantera were very good before even Philip Anselmo joined them. They were very good and well-established at what they did, a very hard-working band. Phil is from New Orleans, like we are. We've known each other since we were teenagers. We've been friends for a very long time.
"I think a lot of the controversy was media- and fan-driven more than anything. I was friends with Darrell as well. I've been friendly with Rex a long, long time. I've known these guys for years.
"Were we doing what they ended up doing before they were? In a way, there was things that we were doing that they eventually did and we were doing them first. But that doesn't necessarily mean that there was any kind of blatant rip-off or anything."
Exhorder split in 1993, before returning in 2019 with their third album Mourn the Southern Skies.
Meanwhile, Anselmo and bassist Rex Brown have recruited Zakk Wylde and Charlie Benante to replace the late Abbott brothers Dimebag Darrell and Vinnie Paul for a series of live dates under the Pantera banner.
Thomas adds: "It's a frustrating thing to me, because I guess it's kind of like the poor man's version of Metallica versus Megadeth. I don't think it needs to be that big of a conversation anymore.
"Basically, we've reformed back in 2017, and we're still going strong, about to do our second album in that timeframe. And they're putting some shows together with some friends to bring the band and songs back to life, which I think is a great thing. So there's room for both."