As one of the Uproxx commenters notes:
Leonard started Final Jeopardy with $37,000. He had $3,000 from the previous evening. Therefore, wagering nothing, the most he could accumulate was obviously $40K. Nilai entered Final Jeopardy with $14,400. He ended the previous night with $19K. IF NILAI HAD WAGERED IT ALL (or even a majority) AND GOTTEN IT RIGHT, HE WOULD HAVE WON AND LEONARD WOULD HAVE LOOKED LIKE A HUGE DINGUS!(edited for clarity). He's right, isn't he? Is there some higher-level Jeopardy! math I'm missing?