The rapid adoption of generative artificial intelligence in legal practice has produced a regulatory inflection point. Nearly 950 documented instances of courts addressing AI-generated fabrications in legal filings, combined with the issuance of ABA Formal Opinion 512 and Texas Professional Ethics Opinion 705, have established that lawyers who deploy generative AI tools without adequate verification protocols face sanctions, malpractice liability, and disciplinary action. This memorandum synthesizes the governing ethical framework, examines the empirical evidence on AI reliability in legal contexts, analyzes the emerging sanctions jurisprudence, and proposes a risk-graded implementation model — the "Lawyer-in-the-Loop" framework — that satisfies professional responsibility obligations while capturing the efficiency gains AI tools offer. The memorandum further addresses the nascent evidentiary challenges posed by deepfake technology and recommends firm-wide governance structures for sustainable AI adoption.