So without any ground based Navaids, using an Inertial Ref system that was only accurate to 1.99 NM per hour, there is absolutely nothing wrong with making up a descent based on that IRS accuracy? A descent that puts you IMC below MSA in the hope that you will get a good look at everything VMC when you get down there. And most aviators on here siding with the crew completely agree that from an airmanship point of view they would happily do the same?
There would never have been a single comment on the CVR regarding the weather conditions if they had remained within the company SOPs.