AI assistants now influence procurement evaluations, customer research, compliance interpretation, and internal operational decision making. These systems generate compressed judgments that may include misstatements, contradictory suitability assessments, substitution events, and exclusion effects. Existing monitoring and optimisation tools observe outputs but cannot provide reproducible, audit grade evidence of how external AI systems represent or evaluate enterprises. This paper defines the external reasoning governance layer, catalogues the failure modes that create material exposure, sets out the requirements for evidential control, and outlines AIVO’s methodology for controlled testing, stability measurement, and structured evidence generation. The paper concludes with implications for enterprise risk management, governance oversight, and regulatory readiness.