“If Rabbi Hershel Shechter believes for certain that swordfish is kosher, he should video himself cooking it and then eating it”
Why? Is that how halacha works?
“Wouldn’t we all agree?”
Absolutely!
Of course , the Agudas Harabanim allowed swordfish too
http://www.hebrewbooks.org/pdfpager.aspx?req=12060&st=&pgnum=18
The history of swordfish is actually quite fascinating, the opposition was largely driven by Rabbi Tendler, who wrote a teshuva in the Jewish Observer April 1968 that really turned things around , it baecame a dividing line between Orthodox and Conservative when the two were more similar several decades ago