TIC 38699429: an unconfirmed transit candidate around a faint nearby M dwarf, from a hash-registered search of public TESS-SPOC light curves

We report an unconfirmed transit candidate on TIC 38699429 (Gaia DR3 4676612253064169344; Tmag 15.27, Teff about 2914 K, d about 57 pc), a faint nearby M dwarf with 31 TESS-SPOC full-frame light curves (Sectors 1-69) and no 2-min data. The signal has P = 11.718179 d, a template depth of 24621 +/- 893 ppm (about 2.5 %) and a measured duration of about 1.4 h. It was the only survivor of a pre-registered coherent multi-sector search of 400 M dwarfs without 2-min data; the threshold comes from 110 control stars and 331 scrambled runs (at most 0.05 expected false positives for the noise in the scrambled data). The ephemeris was written to file before Sectors >= 86 were looked at (its hash was recorded in a hash file only afterwards), and the signal is recovered there (z = 10.8). A blind reproduction and a counter-evidence analysis, both by AI instances of the same model family using the same photons, find it real, periodic and located on or near the target. It is not validated: TRICERATOPS FPP 0.19, NFPP 0.16; the pixel position test has only moderate power (p = 0.087); a bound faint companion, an unresolved background eclipsing binary and a twin eclipsing binary at twice the period are not excluded; the radius of about 2.8 Earth radii holds only for a single star. The signal is also already a public SPOC data-validation TCE (generated 2024-09-14, multi-sector run S56-S69) although the star is not a TOI or CTOI as of 2026-10-25; no claim of first detection is made. The analysis was AI-assisted (Claude, Anthropic); the reviewers are AI instances, not independent human replications.