To this I'd like to add just a few words: even if assuming B, C and D would be accurate 99.9% of the time and have very low probability of causing misunderstanding, when you encounter a person with quality A, for any person in those 0.1% it will happen Every. Damned. Time.
This is a very solid reason to forgo that particular label and even aquire aversion to labels in general.
Aside from that: could Sarah use her illusion spell while inside of her illusion spell and thus gain truly ludicrous time acceleration Inception style? And yes, I think the loss of accuracy clinches it for complicated equipment like computers.
edit: there were no typos here, you haven't seen anything.