git grep -F doesn't behave like grep -F?

Hi folks,

git grep -F is documented as: "Use fixed strings for patterns (don’t interpret pattern as a regex)."

whereas grep -F is documented as "Interpret PATTERN as a list of fixed strings, separated by newlines, any of which is to be matched."

This accurately describes how they behave, which means that git grep -F with a pattern containing newlines never matches anything (at least as far as I can see). Is this intentional, or an oversight? The ability to grep -F for a list (e.g. the output of another grep) is pretty handy...