So if it was the BBC's comment (I never said it wasn't by the way) who in the bbc told Fiona Bruce to make it and why? I'm talking specifically about the "it was a one off" element.
It's also conjecture to say she needed to include the "one off" part of the statement for legal reasons because neither Bruce not the BBC have said as much. So you've jumped to some conclusions yourself there.
I'm not a lawyer but I do have a degree in law and a big part of my job involves applying law so I'm not coming at it from a completely uninformed position when I say I can't see any legal reason to have included that bit. Happy to be corrected if a lawyer explains otherwise.