It's not just the riffing, I think the whole band is pretty loose on Unquestionable Presence when compared to a band like Cynic. It's not a bunch of college trained jazz/metal musicians, it's a bunch of hacks with natural flair trying to play crazy technical metal with some jazz influence. Obviously the band are more tight on Elements and the drummer has better trained technique than Steve Flynn, but really the album is a pretty boring listen when compared to UP. And yeah the production doesn't help either.
Also I listened to a bunch of YouTube videos and you're right, he can't play Mineral. He also can't play Mother Man. I actually had to stop Mother Man because he was butchering it so badly.