What's the rationale behind choosing something like: "Whenever some charges/casts Disjunction/summons Cthulhu" when you could pick: "Whenever I say Blank"?
A) You could be asleep/stunned/paralyzed/in a zone of silence/caught blind-sided/flat footed/hit by an invisible spell
B) Every GM I've seen (and whenever I GM), it's ruled as being exactly the same as a command word trigger. After all, wands can be triggered by "whenever you say Mellon", but it's still a standard action.
But for wands you still need to apply at least some special knowledge about spellcasting. Not for Contingencies, that's really just saying the word.
Still, the incapacitated/flatfooted argument is enough to make it trigger in some other way than through speaking of course, plus as Jameswilliamogle said, it comes across a lot less cheesy.
