if the
relevant RVR at the aerodrome is at the time less than
the specified minimum for landing
Well, the RVR when you went below 1000' was above limits, so no problem there. You reached DA and had the required visual reference to land, so also no problem.
In JAR OPS, an approach ban only exist before the FAF (or point) therefore once passed that point you can continue to DA even if the RVR drop below limits, if at DA you have the correct visual references you can land irrespective of the reported RVR, if you don't have the required reference, go around.