43 Inches - very good post.
The 1983 Incident was not the only such case of aircraft being caught-out in PER (for a variety of reasons).
If memory serves correctly, the fallout from the 727 case revealed a QF aircraft that very same evening assessing the need to ditch (happy to be corrected there).
The prevailing consensus is that additionally on a later occasion, a 767 actively considered ditching. QF colleagues related the case to me at the time and I believe sim sessions were subsequently developed with such a scenario in mind.
I'm sure there are QF contributors who can validate (or not) the above.
Naturally, general criticism at the time was: "Why would you even consider ditching an aircraft due only to fog causing vis/RVR below minimums". Of course that's a reasonable assumption and it was used as 'proof' of how QF pilots were so rule-oriented that they couldn't use common-sense.
However there must have been much more to the story than emerged - there always is.
Nonetheless, I think that there is more to the story than mere rumor and it might be a worthwhile discussion point.
After the 727 case, DoA/CASA absolved themselves of responsibility to provide WX updates to enroute aircraft as had previously been the case. The onus for this then lay with the crew. With this increasing trend to make literally everything the responsibility of pilots, the PER scenario is probably even a more relevant discussion topic...