see, I would have rolled if a GM told me to, or said it out to the group: SC check or lore, search, etc.
now, if I see someone else doing something, I usually hold myself back... I think, I haven't really thought of it. I mean, once its pointed out, I'll watch for it, but before now, I wouldn't have and if I see half the group rolling willsaves, guess what I'll be doing?