The lyrics are coming from the Mississippi Sheiks version of the song, the original and very first. This song became a bluegrass, blues and folk standard over the decades. There might be some significance to the fact that the Sheiks were black and their version predated the many countryish versions by whites. For example, Turner might identify with the Sheiks more than with Bill Monroe.
The way the slide and quills work together is great.
Update later: it seems most likely to me that it’s Otha Turner’s *age* causing him to use the original Mississippi Sheiks lyrics. It took a while for this song to spin off all the related versions, and in the meantime it was a great song just as it was. The original came out around 1930. Turner was born in 1907, so was around 23 when the Sheiks were doing their thing. That would be a perfect age for him to learn the original just as it was.