Could you post a link to that video?
If by above you are referring to the below quoted text, then that text is not correctly formulated and it should read, as a few paragraphs above in the same manual is mentioned, that the relays are closed because of an EXTERNAL fault (not internal fault), and are closed to prevent further damage to the inverter MPPT input. Manual quote: “When the relays are closed, the PV array is short-circuited to prevent PV power from entering the SmartSolar MPPT RS.”
Usually those relays will close when a thunderbolt is striking close to the panels. The momentary very high voltage induced will make those relays to trigger/close and therefore the fuses close to the relays will blow and forbid the high voltage to reach the internals.
But all this, IMO, is just wishful thinking and there for the rules to be followed.
No installation will survive. Not even a close event, not to mention a direct strike…
