Yes case will not be dismissed, but I'm guessing his case will be rejected by the DA. He has a very solid case without any impaired driving citation and BAC under .08. Only hurdle I see is PBT can be used to show declining BAC, but I'm guessing DA will not wast his resource on a case he can lose.
Clearly, you have never been involved in a DUI case. I have. And, I have made dozens in San Diego County courts.
Now, if the case is written poorly, or the officer has a lack of training and experience, it is very likely that the case will not be pursued - or, a plea to "wet" reckless will be offered up. However, from what the OP wrote, he failed to satisfactorily complete the SFSTs since two "clues" are all that are required to opine that they were not successful, and he scored two, three, and "failed" on the three standardized tests.
I'd say that perhaps a quarter of DUI cases do not have observed bad driving ... bad driving doesn't make the case. It certainly helps, but it is not required. It is simply impairment that must be shown beyond a reasonable doubt, not bad driving. And if the driver failed the SFSTs and the officer is capable of articulating this effectively, the DA will likely make the case.
Now, things MAY have changed in San Diego County and they may no longer pursue cases under .08 ... my county does that, but my DA tends to abhor going to court. When I was in San Diego, they prosecuted DUI drivers regularly - even at .07. The lowest I made a case on was .044 in that county, so they DO (or did, 7 years ago) prosecute them.
More than likely they will offer a plea ... if not accepted, it will come down to the confidence the ADA has in him or her self, and in the officer's ability.
- Carl