I did know about the Garko rumor when I watched the film the second time, so I kept an eye out for him. He is nowhere in the film. Bosch himself commented on this rumor saying Chet Bacon was a “third-rate regional actor”, often confused with Gianni Garko, (according to Jesús Ángel González López on Don Herron’s blog "Up and Down these Mean Streets"). Heaven knows why.
I didn’t know there was an issue about Camardiel, so I didn’t particularly look for him. It seems he is the sheriff, Noonan, as stated on the SWDB’s page on the film. Here some mugshots (actually, I think he has lost some weight):
Max Thaler is obviously played by José Daniel Martinez (as Daniel Martin), as is also stated on the SWDB’s page.
The official Bosch filmografia got it wrong, the SWDB got it right.