The State of California accidentally legalized the sale and manufacture of the drug PCP, also known as angel dust, because of a small error in a massive revision of state drug laws. "We're human beings; these things do happen," said Assemblyman William J. Filante (R-Greenbrae), sponsor of the 100-page revision of the California Uniform Controlled Substances Act, which took effect Jan. 1. The mistake, which appeared in the law's fine print, is expected to have little impact. Still in force are laws against possession of the drug and the chemicals used to make it. Filante said he planned to submit legislation to correct the errors, which the attorney general's office spotted last month while revising a draft of another bill.