First I've heard of this. Would like to see some examples if true since I've mostly heard the opposite, although that could simply be due to YYH being treated better than the dub for Z and GT at the time.
Going off of memory here, though I did a quick Google search to see if similar complaints were brought up and that it wasn't just an isolated case. Granted, the people who brought it up didn't always have a preference for dubs, but they felt that the dub started falling apart after the Dark Tournament, adding things in that didn't make sense narratively, putting in jokes where they weren't appropriate, or making contradictions. One example that was given was that in the original, Sensui told Yusuke he never cared about his portal and that it was all just to get him to fight him, then gets his ass beat by Yusuke who tells him how stupid it was for him to go through all those tests for a stupid reason when he would've complied had he asked him. Then he later mentioned to Sensui, "You didn't care, right?" In the dub, their exchange was changed into something completely different, Sensui didn't even mention he literally went through the trouble just to get Yusuke to come to him, yet in the dub Yusuke still asked him "You said you didn't care, right?" when Sensui never mentioned such a thing.
(Honestly, it's been a while since I last watched the show so I can't confirm how this played out, so it sounds nitpicky, but I'm just paraphrasing what I remember.)
Something I saw on
GameFAQs about the dub had pointed out there was a difference in character personalities, although it was about one of the announcers for the Dark Tournament turning from a good girl working for bad people into a sadist in the dub. I also remember one rant I had found years ago that I can't find at the moment in which the person had a serious hate-boner for Justin Cook after watching his interviews on the DVDs gave them an impression he's just a douche who claimed to everything about
YYH because he read the manga so many times. I have the season DVDs so I'll go take a look and see if these interviews are on there so I can see what they meant by it (unless it's on an older release, if
YYH had a couple of different DVD releases).
But while general consensus is that the dub is good and I don't disagree, I do remember thinking when I first watched it a couple of years ago is that it
has been showing its age, like you could definitely tell it was one of Funimation's first (serious) projects. But in comparison to
GT, yeah, the dub was handled better, though both are enjoyable/tolerable watches.
So if Justin Cook is an okay guy, he may not have to get dragged into this mess, but he was one of the original founders, right? It's probably why he's been mostly relegated to being credited as a producer, I take it? (I don't recall him being cast in anything big in the last few years, anyway.)