This side doing well

Sure looks like it burned up. I don't plant any woody plants at this time of year for exactly that reason. The root ball is simply not robust enough to take up enough water and drip irrigation is notorious for not working well for new plantings. They should be able to take full sun although I find that even here (and I am not as hot as you are) most things prefer a few hours of shade. IF you want to replant these, I'd wait until autumn and in the absence of rain, augment with water from a hose. Make sure to saturate the entire root ball. FWIW we just had our first hot spell and had two days of 100 degree heat and even established plantings showed some burning.

There have been a lot of reports in recent years, both here and elsewhere online, remarking on the decline and death of Silver Sheen across much of CA. Apparently, this cultivar in particular is very sensitive to root rots. And more during the summer months, when irrigation is most common and soils are likley to stay moist overnight. I am not saying this is what's going on with yours but it is a possibility worth exploring.

Pittosporum 'Silver Sheen' Sudden Death

Interesting. mine are all fine and they border my holding area which gets overhead watered every other day. and i have clay soil. OPs look fried to me.

Maybe wait until fall to redo. Interesting link, gardengal.

Lost the entire hedge. Will replace with green hopseed which is more sun and heat tolerant