Options not applying when downloading an entire channel

[TwisX]

I'm trying to download every video on a channel as audio with -f bestaudio. However, when I apply -f bestaudio to an entire channel it does not download the correct format. If I download them individually it works just fine.

Here's my output with -v: http://pastebin.com/HDuix28k

[dstftw]

According to the log provided youtube-dl behavior is correct and both downloaded videos are bestaudio.
First file is -eC9snfGpJY. bestaudio is:

171          webm       audio only DASH audio  154k , vorbis@128k (44100Hz), **2.99MiB**

downloaded file is exactly bestaudio.

[download] Destination: Tobu & Itro - Fantasy--eC9snfGpJY.webm
[download] 100% of **2.99MiB** in 00:07

Same for the second file.