At first it was a mystery to me. What happens is that my keychain light has a tendency to turn on. It doesn't actually stay on it just sort of flickers..
Anyway, it took a while to figure out what caused it because I have quite a bit of tools on the keychain, but I seem to have singled it out to the SAK. When it is in contact with my Victorinox Signature Lite quite "tightly" it seems to happen. Since both have batteries... maybe there is something going on with magnetic fields. I do think that it shouldn't be happening. Any guesses why and how to prevent it other than keeping the tools apart?