Point, that's a shame. (Though if you do check, check for Myrddin, it's more likely to work.) It was kind of an idle thought but I miiight be a Merlin fan. :P

But you're probably right, that sort of thing generally gets caught by natives or Lazarus/Glass or both. (Though it's easy to imagine a magic system that would get around that - if there's a nasty way to exploit someone's spellcasting from afar, I'm not sure it'd be obvious in the target.) Counterfactual-Me is just significantly more paranoid about subtle mean magic.