In Frankenstein, why is Victor seen as a reliable narrator (or not)?

In the novel "Frankenstein" every narrator is speaking
through a first person perspective, so that we as readers can relate to their inner and
outer conflicts, issues, and situations.  It would be very hard for any narrator
speaking from their own perspective to serve as a reliable narrator, particularly when
the situation that they are narrating has affected them personally, or has caused
turmoil in their lives. Just imagine: Could Victor EVER be able to be objective in his
life again telling this story after the can of worms he had just opened? Could he be
fair to anyone connected to the story when he has been the main agent provocateur in
this particular plot? Nobody, not even the creature as the narrator, could fairly be
seen as reliable because each of these characters has a deep conflict to resolve and the
problem was caused by a chain of events that, unfortunately, bound them to one
another.