Answer: I'm not absolutely sure, but what you saw might have been Arbutus unedo (Strawberry tree), Carissa macrocarpa (Natal Plum), or Skimmia. A good reference book (such as Sunset Western Garden Book) will have pictures of each of the above plants and you can compare what you saw to what grows well in southern California. The book will also describe growing requirements for each so you can determine whether these plants will perform well in your garden.
Good luck in your search!
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