In Terminator 2: Judgment Day, a key part of the story is that the "original" T-800's arm and CPU as well as the "new" T-800 must be destroyed to keep them from being reverse engineered and to stop Judgment Day from happening.
But when the "new" T-800 is lowered into the molten steel at the end of the film, part of it is missing: its arm. The T-1000 had trapped the arm in some machinery, and the T-800 tore most of it off to go after the T-1000. The movie never shows John or Sarah Connor retrieving the severed arm and destroying it. After such emphasis was placed on destroying the "original" arm, shouldn't it have been equally important to destroy the "new" one?
Was the arm being left behind in the steel mill a plot hole/oversight? ( And was this ever addressed in any of the sequels?)