The title has been changed to the title the original author used, which seems appropriate. I think HN's title modding is done to prevent rampant link baiting and other titling by 3rd parties, instead entrusting it with the original author
Titles have a context (which the author considered when they chose it). That context doesn't exist when it sits enumerated on the HN front page, invalidating the canonical title argument.
For instance when the author of this piece shared this, they did so under their own twitter account (coupling it with a name), and the supporting commentary "I gave this talk at a CA traffic ticket defense attorney seminar. Comments appreciated.". If these two elements didn't exist, and it was just tossed onto some pile of titles, it would be ignored.
I write a blog about software development, particularly financial and database related matters. I have vague titles like "Dealing with Variance" that makes total sense in the context of my blog and its readership, but is completely meaningless title outside of it.
While I do think there has been good transparency about title changes (a mod usually comments), the whole "what the original author intended" argument is misled.
However, there is also a strong argument to be made that there are good articles with lame titles (such as this one) which would otherwise be glossed over without a title change. Maybe the best solution would be to add a summary field to submissions, restricted to an 80-character, purely factual synopsis of the article's contents. It could show up smaller, beneath the submission headline, like a subtitle.
This way, you gain the benefits of editorialization (providing pertinent info highlighting the article's appeal to HN readers) while minimizing most of the downsides (loss of info provided in the title, misconstruction of the author's intent).