The issue of missing quotes has nothing to do with getID3, but rather whatever program tagged that file.
If you notice, there are two similar entries in the ID3v2 tag:
[TPE1] (aka "artist" -> "Lead performer(s)/Soloist(s)")
[TPE2] (aka "band" -> "Band/orchestra/accompaniment")
In this particular sample file, both values are assigned, and to almost the same thing, but one with and one without quotes:
TPE1 = bonnie prince billy
TPE2 = bonnie "prince" billy
So if you look at [comments][band] you'll see the quoted one, and [comments][artist] has the stripped one.
This is an unusual practice, perhaps, but that's how whatever program tagged it, I'm not sure why. getID3 simply reports what's there.