Couple things about this: first, if there were people on these boards who knew Dan and could confirm that he could be, at times, arrogant, rude and abrasive (which is not exactly unheard of for a highly credentialed law professor), those people would never trash the memory of their friend by detailing those points. So it's likely only "Team Wendi" folks that are likely to say anything along these lines. Hence you're not going to get the full story, or at least a credible version of it, in this or other public forums.
Second, and more importantly, why do people seem to care about the sanctity of Dan's character so much? Here and especially on the Reddit DM board people act like it's sacrilege to even suggest DM was less than perfect and may have had some role in causing the divorce. Putting aside the implausibilty of that position (everyone has some bad qualities, and I'd wager that in 90% of divorces both members of the couple have contributed to it), why should this matter?
Let's assume for the sake of argument that Dan, like all of us, had his flaws, and that those flaws were occasional bouts of arrogance, rudeness, or abrasiveness. That would still make zero difference to the immorality and illegality of what happened. I know some people who can act rude, arrogant, etc. Doesn't mean they should be killed.
There's a lot of good analysis and insight on these boards. But there's a lot of simplistic, vengeful moralizing as well that creates this fake manichean dichotomy between Dan as some kind of saint and the Adelsons as "evil" or "vile" or "disgusting." The Adelsons did something terrible. This makes them criminals. They deserve to be tried and punished. I hope this continues to happen. But I don't see the point or appeal of turning a complicated story about real people into reductive justice *advertiser censored*.