Your question is Late-Cycle Critical Defect Escalation. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Tell me about a time you found a critical defect very late in the development cycle, such as during final regression or pre-release validation. How did you assess the risk, communicate it to the team, and influence the release decision?