In Thomas Hardy's "The Man He Killed", what is the purpose of the title being in 3rd person POV, but the poem is in 1st person POV?

The poem "The Man He Killed" is told to us by an unnamed
narrator (a man in a bar) who overhears a one-sided conversation (a kind of dramatic
monologue) made by a soldier who killed a man.  Remember, there's three guys: the
soldier who killed a man, the man he killed, and the narrator.  Even though the soldier
does all the talking, he's not really the narrator.  The narrator simply transcribes
what he says and relays it back to us.  Therefore, Hardy uses vague pronoun usage to
juxtapose the men (who is friend and enemy?) and to show the irony and confusion of all
involved.

So, even though the title "The Man He Killed" is
third person point-of-view, the dialogue has been filtered to the reader through the
original listener, who serves as an imbedded narrator, a kind of outside speaker.  Since
the poem is one-sided conversation (it's all quotes), this imbedded narrator never truly
speaks in his own poem.  He is thus in the same position as the
audience.

Why does this imbedded speaker never comment on
the dramatic monologue?  Why does he never insert his own "I" in response to the
soldier?  He knows that any commentary is unnecessary.  Also, he may not have even been
talking to the solider: he may have only overheard this in the bar.  The soldier speaks
so naively and ironically, using so much bad (circular) logic, that any words of his own
would diminish the humor and irony.  Some things are better left
unsaid.

The poem is rife with irony, including the title.
 In it, Hardy shows relativism and perspectivism using irony and POV shifts, both of
which blur the lines between friend and foe, speaker and listener, soldier and civilian,
patriotism and murder.  In short, the pronoun confusion mirrors the soldier's moral
confusion.

As a side note: Tim O'Brien's short story "The
Man I Killed" is told entirely in third person.  More irony,
huh?