spirit_66: Some games don't include any difficult decisions to make and so could easily show up no fault. But I agree if it happens on more complex games, then it's either suspicious or you're dealing with a very good player. I would expect most games against nabla to show no fault on his part, but only occasionally for lesser players like myself.
Can you post a link to a game or two you're suspicious of so we can take a closer look.
I don't think you should be suspicious of aaru - I really don't believe he's the cheating sort (based on my experience, I enjoy playing him) and anyway, he has far too many games on the go, to have time for it!