Reference for Bava Kamma 80:13

רב פפא אמר מדסיפא רשות משנה רישא נמי רשות משנה ורישא היינו טעמא משום דכל מקום שהולך שם בעליו עליו:

'If it was declared <i>Mu'ad</i> while in the possession of the borrower, and [after it] was returned to the owner [it gored again], the owner will pay half damages while the borrower is exempt from any liability whatsoever.' Does this concluding clause [not appear to prove that a change in the] control [of the ox]<span class="x" onmousemove="('comment',' I.e. from the hands of the borrower to those of the owner. ');">¹²</span>

Jastrow