The Hanafi discussion illustrates an unrestricted financial duty through the effect of loss of zakatable wealth after liability has arisen and before payment.
Where the relevant property is genuinely destroyed in its entirety, the text discusses the resulting lapse of liability. This should not be confused with intentional disposal of wealth in order to evade payment; voluntary conduct and involuntary destruction are legally distinct questions.
Key point: the duty is related not merely to the passage of a first possible instant but also to the cause and subject matter upon which liability depended. One must not mechanically treat every delay as expiry of a set period.