umm, rhett, s/he said turning it on
, not off.
now, i'm not an expert, but:
1. jedi are supposed to be aware of things like that.
2. a jedi should know what it takes to turn on their lightsaber, even accidentally. i mean, come on, they did build it themselves.
3. as rhett did somewhat point out, some lightsabers can't activate unless your holding them, or you consciously activate it with the Force, which would in turn prevent it from accidentally turning on.
hope that helps.