In-Flight Rollback on SGLang: A Sentence-Level Check Cut Wrong Legal Answers From Memory by 83 to 86%

legal-rag-verifier checks each sentence while the model writes it, cuts a rejected one and rewrites it with the statutory text added. 240 UK statute questions answered from memory, 14 October 2026: answers holding a wrong sentence fell from 132 to 23 for Qwen 27B and from 198 to 28 for Qwen 2.5 7B. After a real error, the default retry was wrong again 71 times in 95, and a retry with the provision added at the cut 16 times. With the source already in the prompt, Qwen 27B had 4 such answers with the loop and 4 without, against 3 for Gemini 3.8 Flash and 8 for Claude Opus 4.6.