From: Rabbi Akiva Eiger
To: Unknown recipient
The teshuva analyzes whether the word 'או' (or) is genuinely needed to divide cases in the verses governing four/five-fold payment and bailment. Rabbi Akiva Eiger explains that under Rav Nachman's accepted view, a conjunctive 'vav' would be ambiguous since an ineffective sale before ye'ush and subsequent slaughter of the same animal are both possible, making 'או' necessary. He further resolves the parallel question about the shomrim verse by noting that a 'vav' construction could be misread in a pluperfect sense, as attested in Yeshayahu 64:4, requiring 'או' to clarify that death and breaking are independent cases.
Source: Shu"t Rabbi Akiva Eiger §187