There was an error in the Low-Q Season 4 BT download. The file named "The Pilot - Part 2" was actually a duplicate of "The Pilot - Part 1". I have corrected this now. The new Season 4 (Low-Q) download contains both parts:
Season 4 (Low-Q)
For those who downloaded the old version and received two copies of Part 1, here is a single file download of Part 2:
The Pilot - Part 2
Sorry about the error.