IIRC) We have a system of P’sak. B’shaas H’Dichak, one can “rely” on a kula (a shitta that is not paskened by) due to it being better to the alternative (such as hefsed meruba, for example). That is not the Halacha that should be followed in the normal case. “
Ok. But Shaas ha’dchak is NOT a kula, it is about finding a LOOPHOLE that just squeaks by, in the event of an emergency. And one could argue, that that is a whole other set of halachos that come under the “In Case Of Emergency” header. Meaning: This and this is the halacha, but ICOE this OTHER thing is the halacha that may be followed if needed (but ONLY because of the emergency involved). Emergencies i.e., pikuach nefesh on Shabbos, often abrogate certain halachos that must ordinarily be followed to the T.