Saving throws question (critical fail/success)

I understand 1 is always a failure and 20 is always a success, I cast a know alignment spell on Vitral (wizard imprisoned in the Underdark, who asks you to guard the portals while he searches for trinkets on the other side) and this happened... 
then I went to see his stats on Near Infinity and:

so nothing, strange here, I even remember having negative numbers as saving throws but still failing every once in a while playing some time ago, so what's going on with this last patch? did it change that rule? I'm playing on core rules btw and I'm also aware that the know alignment spell description says some magic devices could prevent the know alignment spell from working, but he seems to be carrying nothing else than a staff and an item that doesn't have a description on NI. Didn't test much more on this session but anyway my concern is that I'd like to know if the 1 fail, 20 success rule on saving throws is still a thing, or does this creature have an exception. Thanks!

then I went to see his stats on Near Infinity and:

so nothing, strange here, I even remember having negative numbers as saving throws but still failing every once in a while playing some time ago, so what's going on with this last patch? did it change that rule? I'm playing on core rules btw and I'm also aware that the know alignment spell description says some magic devices could prevent the know alignment spell from working, but he seems to be carrying nothing else than a staff and an item that doesn't have a description on NI. Didn't test much more on this session but anyway my concern is that I'd like to know if the 1 fail, 20 success rule on saving throws is still a thing, or does this creature have an exception. Thanks!
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Comments
None of this behavior is new to any recent patch. It has always been this way, but BG's often confusing mechanics tend to make things like this less than apparent.
Originally, each voice set had a spoken line for every roll of 1 and every roll of 20. I'm not sure if the voicing is working consistently any more in the EE's.
Sad fact: When Beamdog was working on the voice acting for BG2:EE they apparently forgot to have Mark Meer do Rasaad's critical hit line. The result of this is that when Rasaad scores a critical hit, text will appear in the log for his line, but he will not audibly say anything. For my own runs I decided to fix this issue by setting one of his battle cry lines to also be his critical hit line (namely the one where he says "Taste my Foot!").
I always had the math part pretty clear back in the day, but I played many sessions sporadically some time ago thinking that me and the mobs/creatures were failing saving throws at one of the extremes of the dice and succeding always at the other side. Been a while since I played without mods too, ever since I got the EE I've only played vanilla. I also had forgotten that nifty -5 penalty to the saving throw in the cleric AoEffect silence spell.
but luckily in the BG games, the "DCs" per se aren't so extreme that it would make it so a level 40 dwarven fighter with a fort save of +50 is losing to a poison DC of 12 because he rolls a 1
for the most part in the BG series basically everything is a DC of 20 ( your saving throw is trying to beat the d20 die ) and its a relatively effective mechanic for the whole series, because even in the ToB chapters, there are things that give penalties to saves, and the item placement in the game is pretty well balanced as well where saving throws are concerned
That's why I've recently taken to playing NWN on normal difficulty. That setting removes critical hits for enemies. I only wish I could also remove critical hits for my character, to make things more even. I truly hate the critical hit system in NWN. If an enemy is using a weapon with 3x or 4x criticals and rolls a 20, that's a game over for any character lower than 10th level as soon as the opponent rolls a 20. I think it takes all the fun out of the D&D game to make it *that* dependent on 1 and 20 dice rolls.
also there is one item in NWN which is nice, the helmet that makes you immune to mind influencing, its just a god send, there would have been SO many battles i would have lost thanks to the "roll a 1 and automatically fail nonsense" but because i was wearing that helmet i survived the encounter, yup, can easily pass the save with a 2, but apparently the distance from 1 to 2 in DND is the distance from earth to the nearest quasar, while the distance between a 2 and a 3 is the distance between your eyes to your nose