What is the test for rejecting part of the testimony of a witness?

The court 'properly may reject part of the testimony of a witness, though not directly contradicted, and combine the accepted portions with bits of testimony or inferences from the testimony of other witnesses thus weaving a cloth of truth out of selected available material. [Citations.]' Nevarov v. Caldwell, 161 Cal.App.2d 762, 777, 327 P.2d 111.

All evidence in the record must be considered regardless of whether it is intrinsically competent and whether it was admitted over objection or without objection. '[W]e must take the record as we find it. We cannot strike or disregard any evidence favorable to the prevailing party merely because it was erroneously received. [Citations.]' Waller v. Southern Cal. Gas Co., 170 Cal.App.2d 747, 339 P.2d 577, 583.