Draco know that Harry can beat Veritaserum. And the chances are decent that he'll be well enough to attend the trial
Draco only observed that Harry said he was an Occlumens. This was a line of thought that Draco wasn't particularly able to follow though on anyhow (since he didn't have the Veritaserum and didn't even know where to get it). He only abandons it when he realizes a more feasible test exists (via patronus).
Keep in mind Draco's first impulse is that it was a complete lie, and he knows Harry (and what Harry can do) personally. Nobody else would believe an 11 year old would be an occlumens this young. Plus, Harry has enough evidence incriminating Quirrell to make any charge stick.
EDIT: New discussion thread here.
This is a new thread to discuss Eliezer Yudkowsky's Harry Potter and the Methods of Rationality and anything related to it. With two chapters recently the previous thread has very quickly reached 500 comments. The latest chapter as of 17th March 2012 is Ch. 79.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author's Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system. Also: one, two, three, four, five, six, seven, eight, nine, ten.
As a reminder, it's often useful to start your comment by indicating which chapter you are commenting on.
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: