Unfortunately, that's where a lot of people start and finish. Henry tried and found wanting at the hands of one critical academic. Having looked at the life of the man, his selfless efforts while heading the Church Missionary Society, his advocacy for Maori and his frustration that the Treaty wasn't being honoured after 1844 I see a very different story.
Governor Grey saw him as a troublemaker and made claims about his land ownership at Pakaraka and along with Bishop Selwyn had him dismissed from the CMS.
The reality was he paid twice the going price, the land was difficult to farm, it was farmed by his sons who would have received some allocation had they been in Australia for example, and he employed Maori and provided for them from his farming.
Henry Williams was a friend to Maori and is recognised as such in a monument fully paid for by Maori in the Bay of Islands. He was certainly not a villain.
If you need more information read my book Bible & Treaty or this article I wrote which addresses many of these issues. Copies available for $45 plus postage Email: email@example.com