Thanks Guys,
this is great feedback.
The quote from JAR is almost exactly what our Ops Manual says. The confusion (in my mind) is the term vis/RVR. As you point out, had the RVR not been available, we could have continued the approach.
However, it is possible that we might have lost the required visual references very late in the approach, causing a late GA.
Thanks for the info, I am away for 3 days but do keep the feedback coming.