There was one other factor that contributed to the early-mid 90s decline in So Cal real estate that I have not seen mentioned here: the 1994 Northridge earthquake. At that time, I lived about 20 miles due East of it and remember clearly. Many of my friends and co-workers were displaced, not only in the valley but in Hollywood, West LA and Santa Monica. Some people left purely out of fear. Houses in Northridge and Chatsworth and most other parts of the valley to lesser degree could be had for a song for the follwing 1-2 years.
I do not know if there was a direct effect on SD real estate, but I imagine it had ancillary effects.