Need help/guidance on Strings techniques in LP

So, all notes are played in one stroke?

Perhaps not all of them, but that's the general idea, yes.

I tried to find a video describing this; around the 5:30 mark and following this technique is shown (albeit in low position):

It's important to think about what's actually happening here (and perhaps this gives us an idea why this is hard to emulate): We want a strong legato feel (with each note blending into the next one); given the high speed of the downward run this makes changing the bow direction from note to note impractical. Hence one stroke.

Next question: Where is this material played? The run stretches over two octaves and ends either on the D or Eb above middle C. Now let's think of the violin strings and their tuning: G-D-A-E. So the run starts around the octave position of the E string (I believe the run starts with an Eb).

The higher we get up the fingerboard the trickier a stable intonation becomes (because the distances get smaller and smaller). Now couple this with high speed and a group of players and you get a thick and somewhat "slurry" impression.

The problem in recreating this lies in the combination of all aspects: The speed might lead to a slightly "looser" intonation; and since the timing is completely dependent on the left hand you might also get slight timing discrepancies. Add to this a lush reverb an you get this almost glissando-like sound.