It's interesting. From what I've read, VDA was approached by a small (very) publishing house with an offer to publish the lexicon in book form, and said "I can't do that because of copyright" and they - the experts, one would suppose - said "Oh, sure you can - your work is scholarly" (moment of professional opinion: it's not, at least not how that's usually defined). I think he was skeptical - skeptical enough that he insisted on a clause in the contract saying "If there's a lawsuit it's on your heads and you pay for all legal fees" and they said, "Okay" by signing it.

It seems that upon signing a contract with them (probably because he trusted their legal department) he may have also signed away his rights to stop the publication should JKR object.

If there's an evil here, and again this is only based on what I've read and a bit of experience with how publishing houses work, I think it's the publishing company. I think they were opportunistic and self-serving in how they defined "scholarly," and I think it's in horrifyingly poor taste (and with really bad judgment) that upon receipt of the information that JKR objected they did not immediately drop the project with an apology.

I don't think VDA should have trusted them as far as he did - but it may be that his worst error was simply in trusting a publishing house to know what they could and couldn't publish.

Anyway. My $.02.