Nothing this is natural, normal behaviour for the shrub. Once the flowers go over they fall off... Just leave the Camellia alone and it will get on and sort itself out ready to flower next year.

Now would be a good time to prune, however, but only if they need it.

Gawd our oldest is approx 15 years... would not think of pruning - not at tall as me yet.

A few varieties are vigorous, willowy growers, and will reach out and grab people if not restrained. That's probably more of a problem in areas like here, or even more so California, where the growing season is 9 months long!

Yes different climate, different pruning needs.