I would agree, as long as that third party has insurance in the event their fix (due to work performed on the high voltage battery pack) causes a failure resulting in the loss of the vehicle and liability from that failure event.
In this specific case, I hope Mr. Benoit or his garage has robust liability coverage (at least $1M, hopefully more), especially if a failure event happens while the vehicle is fast DC charging or charging in someone's home overnight.
(disclosure: Tesla owner who performs his own work)