4 Restatement Torts, 2d, ยง 920A, subsection (1), p 513. See Manuel v Weitzman, 386 Mich. 157; 191 N.W.2d 474 (1971); Wood v Vroman, 215 Mich. 449, 465; 184 N.W. 520 (1921). The rule is so well established that in Brewer v Payless Stations, Inc, 412 Mich. 673; 316 N.W.2d 702 (1982), the parties agreed that a $150,000 settlement paid by General Motors for alleged negligent design of an automobile fuel tank was required to be subtracted from any recovery from a gas station for negligent design of the station and maintaining a nuisance.
He could answer what is or what is not proper practice or the correct diagnosis under the circumstances. Brewer v. Ring, 177 N.C. 476, 99 S.E. 358; Wood v. Vroman, 215 Mich. 449, 184 N.W. 520; Laughlin v. Christensen, 8 Cir., 1 F.2d 215; National Automobile Ins. Co. v. Industrial Acc. Comm., 132 Cal.App. 373, 22 P.2d 568; Thomason v. Hethcock, 7 Cal.App.2d 634, 46 P.2d 832; Updegraff v. Gage-Hall Clinic, 125 Kan. 518, 264 P. 1078; Schamoni v. Semler, 147 Or. 353, 31 P.2d 776; McCoy v. Clegg, 36 Wyo. 473, 257 P. 484; Bockoff v. Curtis, 241 Mich. 553, 217 N.W. 750; Darling v. Semler, 145 Or. 259, 27 P.2d 886. See, also, Boyce v. Brown, Ariz., 77 P.2d 455; 4 Wigmore on Evid., 2d Ed., 454, 455, to a similar effect.