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A1 — Hallucination / Confabulation

High severityNIST AI 600-1 Risk 2EU AI Act Art. 13OWASP LLM02

Domain: A — Technical | Jurisdiction: Global


Layer 1 — Executive card

AI systems produce outputs that are factually wrong or fabricated, presented with confidence and no indication of uncertainty.

AI language models generate text by predicting what word comes next — not by retrieving verified facts. They have no internal truth-checker. When they do not know something, they produce a plausible-sounding answer anyway. A fabricated legal citation looks identical to a real one. This is inherent to how these systems work, not a bug to be patched.

Do we have mandatory verification requirements before AI-generated content is acted upon in any high-stakes domain — legal, medical, financial, or regulatory?

If your organisation uses AI to produce content that staff or customers rely on, hallucination is an active risk today. Courts have held organisations liable for actions taken on AI-generated falsehoods (Air Canada, 2024). You are being asked to approve a verification framework for high-stakes AI outputs and training that changes how staff treat AI-generated content.


Layer 2 — Practitioner overview

Risk description

Generative AI systems produce outputs by predicting statistically likely token sequences, not by retrieving verified facts. The model has no internal truth detector. This is termed "confabulation" in NIST AI 600-1 and is identified as one of the three most significant generative AI risks. It is highest stakes in domains where factual accuracy is material: legal, medical, financial, and regulatory contexts.

Likelihood drivers

  • Model used without a retrieval layer — relies entirely on training data
  • High-stakes outputs not subject to mandatory human verification
  • Users not trained to understand LLMs fabricate confidently
  • LLM used for tasks requiring precise facts, dates, or citations

Consequence types

TypeExample
Legal liabilityAir Canada tribunal (2024) — liable for chatbot's invented bereavement policy
Professional sanctionsLawyers sanctioned for AI-hallucinated case citations (2023–2025)
Financial lossFabricated analyst projections used in investment decisions
Regulatory breachInaccurate compliance advice treated as authoritative

Affected functions

Legal · Compliance · Finance · Medical/Clinical · Customer Service · Research

Controls summary

ControlOwnerEffortGo-live?Definition of done
RAG implementationTechnologyHighRequiredLLM outputs grounded in verified knowledge base. Source citations surfaced to users.
Output verification requirementRiskLowRequiredAcceptable use policy specifies mandatory verification for high-stakes use cases.
Staff training on LLM limitationsHRLowRequiredAll AI tool users completed training on hallucination risk. Completion above 95%.
Hallucination rate monitoringTechnologyMediumPost-launchRate measured on evaluation set monthly. Degradation triggers review.

Layer 3 — Controls detail

A1-001 — Retrieval-Augmented Generation (RAG)

Owner: Technology | Type: Preventive | Effort: High | Go-live required: Yes

Ground LLM outputs in a verified, current knowledge base. Retrieve relevant documents and inject as context before generation. Instruct the model to answer only from provided context and to state when information is absent. Surface source citations alongside outputs.

A1-002 — Output verification policy

Owner: Risk | Type: Preventive | Effort: Low | Go-live required: Yes

Define for each AI use case whether outputs require mandatory human verification before use. Implement through workflow design — not just training. High-stakes domains require verification by default.

A1-003 — Staff training

Owner: HR | Type: Preventive | Effort: Low | Go-live required: Yes

Train all AI tool users that LLM outputs may be confidently wrong. Require explicit verification of any cited fact, case, statistic, or figure. Include real examples of hallucination failures relevant to the team's work.

KPIs

MetricTargetFrequency
Hallucination rate on evaluation set< 2% on factual queriesMonthly
Verification policy compliance> 95% of high-stakes outputs verifiedQuarterly spot-check

Layer 4 — Technical implementation

# Minimal RAG pipeline with citation grounding
from langchain.chains import RetrievalQA

GROUNDED_PROMPT = """Answer based ONLY on the provided context.
If the answer is not in the context, explicitly state that.
Always cite the source document for each claim.
Context: {context}
Question: {question}"""

qa_chain = RetrievalQA.from_chain_type(
llm=llm,
retriever=vectorstore.as_retriever(search_kwargs={"k": 5}),
return_source_documents=True,
chain_type_kwargs={"prompt": GROUNDED_PROMPT}
)

Tools: LangChain, LlamaIndex · Pinecone, pgvector, Weaviate · RAGAS, TruLens (evaluation) · Cohere Rerank


Incident examples

Air Canada chatbot liability (2024): Air Canada's AI chatbot invented a non-existent bereavement fare discount. The Civil Resolution Tribunal of British Columbia held Air Canada liable, rejecting the argument that the chatbot was a separate entity. Landmark case establishing organisational liability for AI-generated falsehoods.

Lawyer sanctions for hallucinated citations (2023–2025): Multiple US cases saw lawyers submit court filings citing AI-hallucinated case law. Mata v. Avianca (SDNY, 2023) resulted in sanctions including fines and required remedial training.


Scenario seed

Context: A compliance team uses an AI assistant to draft regulatory submissions — not connected to a knowledge base.

Trigger: A team member asks the AI to summarise current APRA requirements for AI model risk management. The AI produces a confident response citing Prudential Standard numbers that do not exist.

Complicating factor: Submission deadline is the next day. The team member is under pressure and submits without verification.

Discussion questions: What control failure enabled this? How should verification have been embedded in the workflow? What risk does submitting inaccurate regulatory references create?

Difficulty: Foundational | Jurisdictions: AU, Global

▶ Play this scenario in the AI Risk Training Module — Hallucination & Confabulation, four personas, ~10 minutes.