What is the requirement of proof when a custodian removes a deposited item that was forbidden to remove, and claims destruction due to a visible danger?

Primary text

If a custodian removes a deposited item that was forbidden to be removed, and the item is subsequently destroyed, and the custodian claims the removal was due to the imminent threat of fire, flood, or another obvious danger, while the owner denies the existence of such a danger, the custodian must provide evidence (Bayyinah) proving the existence of the claimed danger at that location. This requirement stems from the fact that establishing such a visible event is generally not impossible. If this evidence is established, the custodian's assertion regarding the destruction of the item is accepted upon taking an oath. No further proof of destruction is required because establishing the cause of destruction in such circumstances becomes difficult.