Hm, not sure, it's still quite CG looking, unlike the original DVD version.
It might be due to the texturing on the ship. The escape pods look like decals to me and there's some stuff on the pod that looks plasticky.
It still looks cartoonish because of 2 areas:
The Production Rendering for the SD-Shot, back in those days, was prabably lighted in a traditional manner by the Lighting Artist(s). Thereby, an object gets sorrounded by at least 3 lights. The main light is the strongest. One weaker light fills the viewablle surfaces of the object with light and the third makes a contour, in most cases.
Well, back in those days, when there were no Raytracing Algos for Global Illumination, Lighting Artists emulated scattered and reflected light by covering the object in something that is called a "light dome".
The SD-Shots, most likely, have a couple of lights, to care for a more subtle and realistic light approach. But this traditional technique would'nt hold up with HD.
The Original HD-Shot, as it seems, just makes use of ONE light source (counting out the light sources attached to the ship, because they dont add much to the overall secondary light bleeding). This is (the) one reason.
The other reason is the usage of materials. The most important factor are the specular properties. They often get defined through two specular maps (actually, one is for glossiness). Standard Rendering/Shading-Models lack the ability to compute Raytraced Reflections(/Specular/Glossiness), therefore they look cartoonish. This is especialy apparent in HD-Shots.
Though, this is another reason the HD-Shot looks a little weak, the SD-Shot-Resolution is too low to identify those properties in this particular footage.
And here is the reason the HD-Shot doesn't have those features: Because it DOES take time and work to re-do the materials and the lighting to accomplish a current gen quality(HD)! And I somehow doubt that he can "just load his scenes with modern software", without having problems. - But then, I'm not familiar with Lightwave.