in my gaming group there is a WoC player that likes to give his characters Armour save below 0, Making it so that when you wound him with strength 4 he still saves on 1+ in the Faq it says "Note that a save of any kind can never be better than 1+. This does not prevent a model
having items or special rules that would take the save even lower, it simply caps the saving throw at 1+. Also, remember that a roll of 1 is always a failure.
Now i would think that this affect the As soo that even if he has as -1 it stops at 1+ so from a S4 attack he would be saving on a roll of 2+, but his argument is that there is nothing that stops that save from going below 1+, since the rules say that the saving throw can't go lower than 1+ and there for even with As-10 he still fails on a roll of 1.