With respect, it could all be interpreted with reference to retained case law. Clause 6(6) says:
“Subsection (3) does not prevent the validity, meaning or effect of any retained EU law which has been modified on or after exit day from being decided as provided for in that subsection if doing so is consistent with the intention of the modifications”.
So the point is being made that, even where there has been modification post exit to retained EU law, you may still find yourself on a case-by-case basis deciding that you can construe that retained EU law, notwithstanding the modification, in accordance with Clause 6(3). If the noble and learned Lord wishes to discuss the matter in some detail later, I am quite happy to take him up on that.