"And no one sees" (Exodus 22:9) - Scripture speaks of a case where there are no witnesses. "No one seeing - an oath of the LORD shall be between the two of them" (Exodus 22:9-10): but if there are witnesses, the householder is exempt from everything. These are the words of Issi ben Yehudah. There was a certain man who was carrying a barrel of wine for his fellow through the market street of Mechoza. It broke in a crowded spot of Mechoza. He came before Rabbah, who said to him: the market street of Mechoza is a place where people are commonly found - go and bring witnesses that you were not negligent, and you will be exempt. Rav Yosef his son said to him: according to whom is this ruling? According to Issi? He said to him: yes, according to Issi, and we hold like him. There was a certain man who gave money to his fellow to buy him four hundred jars of wine. He said to him: I bought them for you, and they turned sour. He came before Rava, who said to him: when four hundred jars of wine turn sour it makes a public report - go and bring witnesses, and you will be exempt. Rav Yosef said to him: according to whom? According to Issi, and so forth. As for Rabbah bar bar Chanah, certain porters broke a barrel of his, and so forth.
When Witnesses Free the Trusted Householder From an Oath
Yalkut Shimoni on Torah 346:16
(וְ)אֵין רֹאֶה, בְּעֵדִים הַכָּתוּב מְדַבֵּר, אֵין רֹאֶה, שְׁבֻעַת ה' תִּהְיֶה בֵּין שְׁנֵיהֶם, הָא אִם יֵשׁ עֵדִים, בַּעַל הַבַּיִת פָּטוּר מִכָּל דָּבָר דִּבְרֵי אִסִּי בֶּן יְהוּדָה. הַהוּא גַבְרָא דַּהֲוָה מַעֲבִיר חָבִיתָא דְחַמְרָא לְחַבְרֵיהּ בְּרִיסְתְּקָא דִמְחוֹזָא. אִתְּבַר בְּזוּזָא דִּמְחוֹזָא. אָתָא לְקַמֵּיהּ דְּרַבָּה, אֲמַר לֵיהּ, רִיסְתְּקָא דִמְחוֹזָא, אִינְשֵׁי שְׁכִיחֵי בֵּיהּ, זִיל אַיְיתִי סַהֲדֵי דְּלָא שְׁנִית בֵּיהּ, וּפְטִירַת. אֲמַר לֵיהּ רַב יוֹסֵף בְּרֵיהּ, כְּמַאן, כְּאִסִּי, אֲמַר לֵיהּ, אִין, כְּאִסִּי, וּסְבִירָא לָן כְּוָתֵיהּ. הַהוּא גַבְרָא דְּיְהַב לֵיהּ זוּזֵי לְחַבְרֵיהּ לְמִזְבָּן לֵיהּ אַרְבַּע מֵאָה דָּנֵי חַמְרָא. אֲמַר לֵיהּ, זְבָנִית לָךְ, וּתְקִיפוּ. אֲתָא לְקַמֵּיהּ דְּרָבָא, אֲמַר לֵיהּ, אַרְבַּע מֵאָה דָּנֵי חַמְרָא, כִּי תָקְפֵי קָלָא אִית לֵיהּ, זִיל אַיְיתֵי סַהֲדֵי, וּפְטִירַת. אֲמַר לֵיהּ רַב יוֹסֵף, כְּמַאן, כְּאִסִּי וְכוּ'. רַבָּה בַּר בַּר חַנָּה תְּבָרוּ לֵיהּ הַנְהוּ שְׁקוֹלָאֵי וְכוּ'.