Ch. 58 shows that Quirrell expected the Auror to dodge
No it doesn't. It shows that Quirrel knows what to say in response to being accused of trying to kill someone to make it look like that wasn't actually his intention.
Given that AK is an Unforgivable, and according to canon the caster must 'mean it' to cast such a spell, I'm fairly confident that Quirrel's explanation is a lie, though I will admit that I haven't checked the exact mechanism for that kind of spell failure - if a not-meaning-it casting of AK would produce a similar visual effect, he could be telling the truth, and it could have been significantly safer than it looked - but in that case, why would he claim that he was intending to move the auror, rather than explaining that the spell was actually harmless?
According to canon, the spell must be cast with hatred. I'm not sure it has to be cast with the intent to be lethal.
- This thread has run its course. You will find newer threads in the discussion section.
Another discussion thread - the fourth - has reached the (arbitrary?) 500 comments threshold, so it's time for a new thread for Eliezer Yudkowsky's widely-praised Harry Potter fanfic.
Most of the paratext and fan-made resources are listed on Mr. LessWrong's author page. There is also AdeleneDawner's collection of most of the previously-published Author's Notes.
Older threads: one, two, three, four. By tag.
Newer threads are in the Discussion section, starting from Part 6.
Spoiler policy as suggested by Unnamed and approved by Eliezer, me, and at least three other upmodders:
It would also be quite sensible and welcome to continue the practice of declaring at the top of your post which chapters you are about to discuss, especially for newly-published ones, so that people who haven't yet seen them can stop reading in time.