Jerusalem Talmud Bava Kamma 4.8

משנה: שׁוֹר שֶׁהוּא יוֹצֵא לִיסָּקֵל וְהִקְדִּישׁוֹ בְעָלָיו אֵינוֹ מוּקְדָּשׁ וְאִם שְׁחָטוֹ בְּשָׂרוֹ אָסוּר. אִם עַד שֶׁלֹּא נִגְמַר דִּינוֹ הִקְדִּישׁוֹ בְעָלָיו מוּקְדָּשׁ וְאִם שְׁחָטוֹ בְּשָׂרוֹ מוּתָּר.

MISHNAH: If one dedicates a bull which is led out to be stoned, it is not dedicated, and if it was slaughtered, its meat is forbidden. If its owner dedicated it before sentence was pronounced, it is dedicated, and if it was slaughtered, its meat is permitted.

הלכה: שׁוֹר שֶׁהוּא יוֹצֵא לִיסָּקֵל כול׳. תַּנֵּי. שׁוֹר שֶׁהָיָה יוֹצֵא לִיסָּקֵל וְנִמְצְאוּ עֵידָיו זוֹמְמִין. רִבִּי יוֹחָנָן אָמַר. כָּל הַקּוֹדֵם בּוֹ זָכָה. רֵישׁ לָקִישׁ אָמַר. יִיאוּשׁ טָעוּת הוּא. וְכֵן עֶבֶד הַיּוֹצֵא לִיהָרֵג וְנִמְצְאוּ עֵדָיו זוֹמְמִין. רִבִּי יוֹחָנָן אָמַר. זָכָה עַצְמוֹ. רֵישׁ לָקִישׁ אָמַר. יִיאוּשׁ טָעוּת הוּא.

HALAKHAH: “A bull which is led out to be stoned,” etc. It was stated: If a bull was led out to be stoned when its witnesses were found to be false, Rebbi Joḥanan said, the first to come acquires it; Rebbi Simeon ben Laqish said, it was false despair. Similarly, if a slave was led out to be killed when his witnesses were found to be false, Rebbi Joḥanan said, he acquired himself; Rebbi Simeon ben Laqish said, it was false despair.