Unfortunately, these types of damage are considered neglect, as warnings were given out to customers before the solar eclipse. Our LensCap insurance plan, which can be added to rentals for a small nominal fee, does not protect from neglect but is an excellent tool for those who are worried about their rental and want to protect themselves from any accidental damage.
(but perhaps not really - there are enough wiggle words in that policy that I wonder if they ever pay out on expensive damage at all: https://help.lensrentals.com/26475-damage-lenscap-protection... )