Joseph:
The prohibition that melacha is forbidden after shkiya is undisputed. The machlokes is over when shkiya is. Rabbeinu Tam has a shitta that is held by large portions of Klal Yisroel. The reason “it is a possible prohibition punishable by stoning” (di’ho safek issur skilah) is due to the uncertainty whether Shabbos starts at shkiya or at tzeis. (And since it is uncertain, everyone agrees we must start Shabbos at shkiya, but not all poskim agree when shkiya is.)
You have clearly never read the Buir Halacha you are attempting to interpret. The Biur Halacha goes through the sugya, starting with the stira in the Gemora, then Rabbeinu Tam’s answer, then the answer of R’ Shiraya Goan, R’ Hai Gaon, Rashi, the Rif, and the Rambam. According to R”T, shkiya starts 4 mil (72 min) after the sun sets and is no longer in view. According to all those who argue, shkiya starts immediately after the sun is no longer in view. So when the B”H says “…mi’yad achar haschulas ha’shkiyah, haynu mi’shuh sheha’chamah niskaseh me’eynainu…” he is clearly to referring to the shittah of the Gaonim and rov Rishonim, who hold shkiya starts from when the sun is no longer in view.
But in case that isn’t enough of a proof for you, let me quote you how the B”H begins the sentence:
“Vi’henay li’maaseh, bi’vaday tzurich li’zuher ki’daas ha’Gra vi’harbaih min haRishonim vihaPoskim hanal di’mi’yad achar haschulas ha’shkiyah, haynu mi’shuh sheha’chamah niskaseh me’eynainu, ho issur gemur shelo laasos melacha, vi’chas vi’shaom li’hukel ba’zeh, di’ho safek issur skilah…”
But don’t take my word for it; crack open a Mishnah Berurah and check it out yourself.
(Btw, I’m makpid for the shittah of R”T myself.)
Do you think the CC held that Rabbeinu Tam and his kehilla were mechallel Shabbos?
First of all, the Chofetz Chaim didn’t make this shittah up. R’ Shiraya Goan, R’ Hai Gaon, Rashi, the Rif, and the Rambam did. The B”H is simply paskening like the majority. So your question really is, did all those Gaonim and Rishonim hold about R”T and his kehillah.
Secondly, I’m not sure why you suddenly decided to make this an issue here.
The Chazon Ish held one may not open bottle caps on Shabbos. R’ Moshe allowed it. R’ Moshe held one may not use a “shabbos clock” on shabbos; the Chazon Ish allowed it.
Did the Chazon Ish and R’ Moshe each hold that the other was mechallel Shabbos?
Or going back a little bit further, did Bais Shammai and Bais Hillel each hold that the other was “shkotzim” or “chopped liver”?
And most importantly, what difference does it make in this point in history?? Shouldn’t we be focusing on figuring out what the Halacha is today, not bizarrely trying to figure out what names we think the Gedolim of the past would have called each other, if they had acted like some of us do today?