Dmitry Gutov [off-list ref] writes:
Either will reset already-staged changes from the said file, which is
an irreversible operation.
But the said file, if it had conflicted, would have had only the
conflicted higher stage entries in the index, no? That is, the
failed merge wouldn't have touched the index for the path if it
already had changes there in the first place.
If you want to keep them then you do not have to reset, but your
question is about resolving conflict only in the working tree and
leave the index clean, so I do not think "git reset -- $path" would
not lose anything "irreversibly".