From my AntiviralList.randomize I obtained these results:
1st time - 2,3,1,5,4,0
2nd time - 4,1,0,2,3,5
3rd time - 3,0,2,5,1,4
I ran a few tests and I think I'm starting to understand what's going on. Because the randomize function has very simplistic rules, it looks like it doesn't work with 3 or less items. In the Tryit Editor I created a sample array with three cases and it always came back 1,2,0. When I added a fourth item it came back as either 3,2,0,1 or 1,2,3,0 every time.