Is Shas Hashmad an objective state? Does it depend on a declaration of the Chachomim? Does it need both, akin to tzaras in a house?
What if some poskim say a situation is not Shas Hashmad, are you required to listen to those poskim because we are meikel by sakanas nefashos?
I pose the following hypothetical: The Chief Rabbinate outlaws kitniyos on Pesach. Anyone caught eating or cooking kitniyos on Pesach goes to jail for a year. Is this Shas Hashmad for Sefardim? Are they required to eat the kitiyos and go jail?