McDunn v. Arnold, 303 P.3d 1279

McDunns leased an apartment from Arnold for 13 months starting June 1, 2008; dispute led to vacating Jan 31, 2009.
McDunns sued Arnold in Gallatin County Justice Court ( Aug 3, 2009 ) for breach of lease, negligence, and negligence per se; Justice Court bench trial on Nov 19, 2009.
Justice Court entered a written judgment in McDunns’ favor for damages, costs, and attorney’s fees totaling $7,059.26.
Arnold appealed to the District Court seeking a trial de novo; she amended an Answer and Counterclaims on Apr 8, 2010 adding new counterclaims.
McDunns filed an Amended Complaint on Apr 9, 2010 adding a claim for intentional and negligent misrepresentation; district granted leave to amend.
Arnold moved in Limine on Oct 21, 2011 to prohibit references to Justice Court proceedings; district denied on Nov 29, 2011; bench trial held Feb 28–29, 2012; Findings issued May 21, 2012; district ruled for McDunns on breach of lease and awarded $1,444.66 damages and $20,697 in attorney’s fees and costs.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Amendment of complaint after Justice Court	McDunns had good cause to amend	Arnold argued abuse of discretion in allowing amendment	No abuse; court permissible to amend
Motion in Limine on Justice Court references	McDunns urged admissibility of prior testimony	Arnold claimed prohibition based on de novo rights	District Court did not abuse; references admissible when integrated into de novo trial
Right to a trial de novo	McDunns contend de novo trial preserved	Arnold argues lower-court references tainted trial	Findings not unduly influenced; affirmed

State v. Stedman, 306 Mont. 65, 30 P.3d 353 (2001 MT 150) (trial de novo concerns when lower-court findings referenced)
City of Helena v. Roan, 355 Mont. 172, 226 P.3d 601 (2010 MT 29) (good cause standard for amendments to pleadings on de novo review)
Unified Indus., Inc. v. Easley, 289 Mont. 255, 961 P.2d 100 (1998 MT 145) (district court abuse for failing to address unraised issue)