From manual page,
git-reset - Reset current HEAD to the specified state
git reset [-q] [<tree-ish>] [--] <paths>...
In the first and second form, copy entries from <tree-ish> to the index.
for example, when we use git reset HEAD~1
it reset our current HEAD to HEAD~1
so when we use git reset 'some-deleted-file-path'
git assume 'some-deleted-file-path' as some commit point and try to reset out current HEAD to there.
And it ends up fail
fatal: ambiguous argument 'some-deleted-file-path': unknown revision or path not in the working tree.