There is a CA website to search to find the handgun models currently certified for sale in California. The Roster of Handguns Certified for Sale: http://certguns.doj.ca.gov/safeguns.asp
For Taurus, the results showed only revolvers. So, the conclusion is that the Taurus 709 slim is not legal to be sold in (including shipped to for transfer) California.

If you go to the California approved Pistols for sale which is right on buds, they do not list the Taurus 709 slim. So I would say it is not California approved. You can get to this list by clicking on firearms at the top. Once there on the left side of the page there will be a store directory where you can select handguns, rifles, shotguns and ect. Under that same directory you will also see California Compliant firearms. Click on that and the it will bring up different categories for firearms that are all californis approved. That's way there is no more guesswork. Hope this helps.

After a lot of reading, it looks like its a no go in California for the Taurus 709. I'd contact Buds or a local shop before buying to be safe anyway. But I don't think its currently on the approved list.