I think it depends very much on what you can get away with, when that depends on where you are and sometimes who your "friends" are!
I am not an aviation lawyer and mostly a bush pilot so that I stand to be corrected on this one but:
There really is such a thing as an "approach ban," imposed for visibility below the required minimums for a specific approach. This can get so involved, when it can depend on where you are on the approach when you are informed of the weather so that beyond a certain point you just press on if you like but short of that point you are "banned" from legally shooting the approach. This must be where declaring an emergency comes into it?
At the other extreme there are many VFR-only airfields which people operate to every day under Special VFR, even when the birds are walking. Okay, one uses the FMS to shoot what looks for all the world like a normal ILS approach, except that the course guidance is in magenta instead of green but that has no legal standing. It is just something that "everyone does" and will continue to do until some optimistic fool pushes a bit too hard and finds an iroko tree instead of the runway threshold. Those who have a problem with this self-select out and go home to somewhere they only have to operate legally, leaving the cowboys to get on with this.
If that Antonov driver had dinged in there, landing in extreme weather on Bermuda, it would have meant a bit of a fuss until the legalities were made plain, when it would have been the Captain's fault for pressing on, probably due to low fuel state, something clearly illegal. As it was he got away with that so, "no basic problem."
How are you going to carry much revenue load to Bermuda with IFR reserves if the alternate is 700 miles off? Nah, 30 minutes extra fuel... Sorted! You get there, you land, period! You no like, back to Siberia with you! Me, strong like bull!
My very first "airline" job was as an FO on a Twin Otter. We were operating to Hilton Head, South Carolina following the rules, only going below the Minimum Enroute Altitude when we were in VMC, since Hilton Head was VFR-only. We had a competitor flying a Navajo Chieftain who would just tell Center "We are now cancelling IFR," and descend VFR in IMC to make his trip when we, just a few miles off, could only see the wingtips on our Twotter so that we would take our load of unhappy punters off to IFR Savannah, Georgia until Hilton Head really did have VMC.
Everyone knew this operator was cheating but how to prove that? It's pretty flat down there so that cheating in that way wasn't exactly unsafe, just flat illegal so that I guess the local FAA office had bigger fish to fry.
I went on to bigger and better things from that, including seeing a head-of-state GV making one totally hairy VFR in IMC approach down in the Niger Delta. We did that but we knew what we were doing; these guys were just making it up as they went along, I guess, so that we saw them make their cloud-break in a somewhat unusual attitude that then called for an unstabilised approach. If they had stacked it with the Prez onboard there would have been the most unholy witch-hunt ever but they got away with it so that "business as usual" just carried on with no lessons learnt. Still going on, in fact...