SND
Ah I see, I thought you meant they had a legal get out, as in that they were ok to go - but understand you mean legal get out as in not to go with respect the owner !
Sorry to say, but I think that ANO article only applies if the RVR is reported. It is not assessable by crews. In UK, Runway visual range is usually assessed electronically, or otherwise by the human observer method in accordance with CAP493 or CAP168. No runway, no RVR report - then 109(2)(b) does not apply in my view.
For instance, at an airport, if RVR is not reported, only met viz, there is no restriction as far as this article is concerned. The same applies to approach minima, there is no approach ban for met visibility, only for RVR.
The list of factors is certainly worth a mention, it helps to enlighten and hopefully prevent reoccurrence.
One thing we can be sure of, a similar accident will occur again. If we can reduce the frequency, then there's progress. I'm sure that's one of the aims here.