Invertron,
There are indeed very good reasons why the mil have safety altitudes. There were possibly also very good reasons why the temporary Release to Service in force at the time of the crash limited the aircraft to operating at temperatures of 4 degrees Celsius or more. As Ark points out, with all the other uncertainties associated with the introduction-into-service of the Mk 2, what confidence could the crew have that the FADECs and engines would still work if they flew below plus 4 degrees? Would you deliberately take an aircraft containing your crew, your pax and yourself into such a situation - risking turning it into an 18-ton glider? Jon Tapper and Rick probably wouldn't (we'll never know for certain - one of the points frequently returned to in this thread); they did know the weather combined with the limitations restricted them to a VFR transit without the luxury of an IFR option.
There was a briefing in force at the time (Crown Indemnity had just gone the way of all things...) stating that aircrew would be held individually liable for any occurrence during operations where rules, regulations or limitations had been exceeded (whether or not such exceedance(s) directly contributed to said occurrence). I, too, wish I'd kept a diary - they were "interesting times".
(Did your quote mean to say: "had that Chinook been at safety altitude where it should have been, would they have not hit the ground?")
(and from the above you'll see that No, I don't have to agree that the aircraft should've been at Safety Altitude. That WOULD have been seen as criminally negligent - a deliberate flouting of the limits in the temporary Release to Service.)