Martz v. Hills Materials, 857 N.W.2d 413

Martz suffered a compensable left-shoulder rotator-cuff injury at Homestake in 2000 (surgery and benefits paid).
In 2002 Martz injured the same shoulder working for Hills Materials; Western National (insurer) initially paid benefits.
In 2005 Western obtained an IME (Dr. Luther) concluding the 2000 injury was the major cause; Western denied further benefits.
Martz’s treating physician (Dr. Anderson) assigned a 15% impairment in 2003 (10% from 2000, 5% from 2002) and later stated the 2002 injury “contributed independently” to ongoing need for treatment.
In early 2006 Western (via its adjuster) paid the 5% impairment and resumed paying medical bills after attorney correspondence; payments continued through 2009. Western later obtained another IME (Dr. Blow) concluding the 2002 incident was only a temporary aggravation.
The Department and circuit court adopted Drs. Luther and Blow over Dr. Anderson, rejected promissory estoppel, and held Hills Materials/Western not liable for Martz’s 2009 condition; the Supreme Court affirmed.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Promissory estoppel — did Western’s 2006 conduct and payments bar later denial of liability?	Martz: Western promised (by adjuster and by conduct/payments) to pay medical bills and abandon the temporary-aggravation defense; he relied and let Homestake’s statute of limitations lapse.	Western: No clear promise to pay indefinitely; attorney letters are hearsay/ambiguous; payments were required by statute and did not preclude later denial when new medical evidence developed.	No estoppel — letters/payments did not prove by clear and convincing evidence a promise to abandon defenses or pay future benefits indefinitely.
Causation — did the 2002 Hills injury remain a "major contributing cause" or at least "contribute independently" to Martz’s 2009 condition?	Martz: Treating physician Dr. Anderson opined the 2002 injury contributed independently to ongoing impairment/need for treatment.	Hills/Western: IME doctors (Drs. Luther & Blow) showed objective evidence (MRI/EMG, comparison of pre/post studies, clinical history) that the 2000 injury remained the major cause and the 2002 event was a temporary exacerbation.	Held for Hills/Western — the Department’s de novo review of medical records favored Drs. Luther and Blow; Dr. Anderson’s opinion lacked sufficient analysis to meet the burden of proof under SDCL 62-1-1(7).

Garrett v. BankWest, Inc., 459 N.W.2d 833 (S.D. 1990) (elements of promissory estoppel).
Hahne v. Burr, 705 N.W.2d 867 (S.D. 2005) (promise for estoppel must be proved by clear and convincing evidence).
Vollmer v. Wal-Mart Store, Inc., 729 N.W.2d 377 (S.D. 2007) (standard of review for agency findings; claimant must prove causation).
Peterson v. Evangelical Lutheran Good Samaritan Soc., 816 N.W.2d 843 (S.D. 2012) (claimant must prove causation by a preponderance; weight to examining physician).
Darling v. W. River Masonry, Inc., 777 N.W.2d 363 (S.D. 2010) (causation to reasonable medical probability, not mere possibility).
Horn v. Dakota Pork, 709 N.W.2d 38 (S.D. 2006) (evidence supporting award must be precise and well supported).
Schneider v. S.D. Dep’t of Transp., 628 N.W.2d 725 (S.D. 2001) (value of expert opinion depends on factual basis).
Hayes v. Rosenbaum, 853 N.W.2d 878 (S.D. 2014) (distinguishing judicial estoppel from promissory estoppel in employer/insurer contexts).