Authorities as the decision cited them, with how this panel applied each one.
McAllister v. Workmen's Comp. App. Bd. (1968) 69 Cal.2d 408; Granado v. Workmen's Comp. App. Bd. (1968) 69 Cal.2d 399
Medical opinion must be based on reasonable medical probability and set forth reasoning behind opinion, not merely conclusions
Applied to reject QME Perrin's cumulative injury opinion as not substantial evidence
From the decision · page 7We agree. It is well established that in order to constitute substantial evidence, a medical opinion must be predicated on reasonable medical probability. ( McAllister v. Workmen’s Comp. App. Bd.
Labor Code § 4663; Escobedo v. Marshalls (2005) 70 Cal.Comp.Cases 604
Apportionment under Labor Code § 4663 must be based on causation with physician explaining mechanism and reasoning with particularity
Applied to reject all QME apportionment analyses as not substantial evidence
From the decision · page 8Section 4663 provides, in relevant part, that apportionment of permanent disability shall be based on causation. (Lab.
Kopping v. Workers' Comp. Appeals Bd. (2006) 142 Cal.App.4th 1099
Defendant has burden to prove existence of prior award and overlap of permanent disability factors under Labor Code § 4664
Applied to deny apportionment to prior industrial factors
From the decision · page 11The defendant has the burden of proving overlap before apportionment under section 4664 will apply. ( Kopping v. Workers’ Comp. Appeals Bd. (2006) 142 Cal.App.4th 1099 [48 Cal. Rptr.
Garza v. Workmen's Comp. Appeals Bd. (1970) 3 Cal.3d 312
WCJ's credibility determinations entitled to great weight based on opportunity to observe witness demeanor
Applied to affirm WCJ's reliance on applicant's testimony
From the decision · page 133d 627 [35 Cal.Comp.Cases 16]; Lamb v. Workers’ Comp. Appeals Bd. (1974) 11 Cal.3d 274 [39 Cal.Comp.Cases 310].) We further accord to the WCJ’s credibility determinations the great weight to which they are entitled, based on the opportunity to observe the demeanor of the witness(es). ( Garza v. Workmen’s Comp. Appeals Bd.