3.05 separate downloads for video+audio and audio

[Nick Payne]

I recently upgraded from 3.02 to 3.05. I notice that with the new
version, when I download a TV programme GiP performs two separate
downloads. The first is shown in the terminal output as being
[audio+video], the second much smaller download as just being [audio].
Why the two separate downloads? If I play the first [audio+video]
download (this file has an hls.ts extension) while the separate [audio]
download has not yet completed, the audio is already there in the file,
so why the second download?

This is what I see on the console:

====================================================================
INFO: Downloading tv: 'Kaufmann's Otello at the Royal Opera House - -
(b099tpcb) [original]'
INFO: Downloaded: 2685.38 MiB (02:30:10) @ 7.92 Mibit/s (hlshd1)
[audio+video]
INFO: Downloaded: 363.78 MiB (02:30:10) @ 7.35 Mibit/s (hvfhd1) [audio]
INFO: Converting to MP4
INFO: Tagging MP4
====================================================================

Nick