How does line 3 in Roethke's "My Papa's Waltz" reveal a deconstructible relationship between the 'you' and the 'I' in the poem?

The Formalist school of literary theory acknowledges that
a text may contain unintentional ambiguities, but despite this, they serve a
demonstrable purpose harmonized with the whole meaning of the poem. The
Deconstructionist school claims the opposite: An ambiguity or contradiction in a text
cannot be resolved to one of its possible meanings. It simply retains
its unresolvability. Thus, a deconstructive critic is more attuned
to the heterogeneous character of a literary work than is the formalist. Line 3 in
Theodore Roethke's My Papa's Waltz  - "But I hung on like death" -
is tailor-made for the deconstructive thesis. The line occurs in the first of the two
mirthful stanzas of the poem: In word and meter, the poet presents a warm domestic
memory of a clumsy but playful waltz with his inebriated father. Yet the ambiguity of
line 3, whether placed intentionally or simply allowed to stand, casts an interpretive
uncertainty over the whole poem. Are the father and the son - the 'you and I' intimated
in the line - engaged in loving horseplay, as typified by the ordered steps of the
waltz? Or is their 'dance' a kind of one-sided drunken brawl, reified in the simile
"like death", where the father "beats" time with a "battered" hand on the boy's head?
The formalist would answer that the ambiguous language is resolvable in the larger
homey meaning of the poem. The deconstructionist would answer that
too great a gulf exists between language and meaning - reified by numerous ambiguities
and omissions - for the reader to come to any certainty about the ultimate meaning of
the poem.