LEGAL PRINCIPLE: APPELLATE PRACTICE – Standard of Review – Primacy of Trial Court in Evaluation of Evidence

This reinforces Principle 424’s recognition of trial court advantages. Trial courts’ unique advantages: (1) seeing witnesses—observing physical appearance, body language, nervous behaviors; (2) hearing witnesses—detecting voice tone, hesitation, confidence, evasion; (3) assessing demeanor—evaluating credibility through non-verbal cues; (4) contemporaneous evaluation—judging consistency, responsiveness, and candor in real-time. These advantages enable: accurate credibility assessment, detecting truthfulness/deception, and weighing conflicting testimony. Appellate courts lack these advantages—they: read cold transcripts, cannot observe demeanor, and miss non-verbal communication. This justifies: appellate deference to credibility findings, limited interference with fact findings dependent on witness assessment, and respecting trial court evaluations based on live testimony observation. However, deference applies only to: demeanor-based credibility findings, not inferences from documentary evidence (where appellate courts are equally positioned), or findings unsupported by evidence (Principle 461 exceptions). The “veracity” assessment is trial courts’ domain—appellate courts generally accept trial courts’ credibility determinations unless findings fall within intervention exceptions. This principle explains why appellate courts exercise restraint in fact interference—trial advantages justify deference.