There’s a difference between the realm of the dead and the realm of the damned.
Sheol isn’t the same thing as Hell.
The example being discussed was a Jew who converts to Christianity. AFAIK, Christians don't believe in Sheol and according to a word search I did, it's not mentioned in the KJV.
If a Jew adopts Christian beliefs, then he must accept that there is only one way to escape eternal damnation, yes?