No conflict so far as I'm concerned; except in establishing which form is the earlier. All traditional forms of a song are valid, but they do need to be put into their proper contexts so that we can understand how they have developed. I'm not a fan of blood-sports, and wasn't aware of the term "bar" in that context, or I probably wouldn't have used the word "mistake"; it may very well have been a deliberate alteration. Not the original word, though, from the evidence we have.