Perhaps badly worded on my part. Limited != none. Clearly SIP has bent the curve. But new cases that are being reported now were transmitted well after SIP came into effect, i.e. are happening despite SIP. And absent other policy changes, we should continue to expect to see more of them. What changes we do see are in the other direction - more traffic, more outside activity, etc.

Practically, increase (or non-decrease) in weekly number of cases in San Mateo and Santa Clara counties suggests as much[1].

[1] https://projects.sfchronicle.com/2020/coronavirus-map/