[jetskindo]

Note to self: add a small mechanical trigger for a parachute for cases of emergency. This will trigger if the drone falls at a certain speed.

[TeMPOraL]

You could add an electromechanical failsafe that would trigger in the event of loss of power - i.e. the safety device wants to deploy itself, but is actively prevented from doing so by the electronics.

[Piskvorrr]

Won't help. An unsteered parachute slows down the fall so that it's sort-of survivable instead of terminal-velocity; there wouldn't have been any significant effect in this specific case.