I see a big problem with the whole sentence constuct "the plane dove 20,000ft" as if the plane had a mind of its own, or else as if the pilots lost control and only got control back in the nick of time.
Instead, from everything I can tell, the pilots were in control, and in response to the sudden cabin depressurization, the pilots executed a rapid, but completely controlled descent, as is standard emergency procedure to a level at which cabin pressure does not lead to the rabid depletion of oxygen from the brain causing death.
Whatever, it was still absolutely a “dive.” No question about it.