Yes, I think the plant can be saved. Not an expert here , but the first thing I would do is cut off any of the leaves with the black showing ( I think it’s some sort of fungus ) , cut the diseased leaves to the ground if necessary. I live in So Cal also, we didn’t that much, coastal beach , but I heard other areas got lots , a mixed blessing.

Um, am looking at similar with my lewisias, after an unusually wet East Anglian summer. As I have quite a few of these, I am going to bite the bullet, bare-root them and see if I can do any sort of clean-up. IME, I have rarely been able to arrest the various phytoptheras and such which swim around doing dire deeds, but the only other option I have ever exercised is the defeatist game of handwringo and accumulated guilt so I dunno - how do you feel about some exploratory digging?

I have often looked enviously on at the lovely and unusual kangaroo paws but have never even considered growing from seed and they are costly plants to risk here in the UK. Do let us know how you get on as I am in a tear-up phase of changing over to a more waterwise sort of garden...so plenty of brutal culling and composting. Very keen to learn about other dryland plants from SA and Australia, as well as the mediterranean...which will also do well in our not terribly tropicalesque UK summers.