Handle unprofessional, prescriptive interviewers

You are mid-interview on a time-boxed SQL screen where the interviewer forbids JOINs and insists on window functions only, interrupts with a personal call, and dismisses edge-case discussions. How do you: (a) clarify constraints and acceptance criteria up front without sounding defensive, (b) manage time and communicate partial progress under strict format rules, (c) surface critical data-quality risks succinctly (e.g., duplicates, late arrivals) while still delivering the requested solution, and (d) recover rapport and keep composure when the interviewer appears disengaged? Provide specific phrasing you would use, trade-offs you would state, and a brief post-interview follow-up note you’d send.