Reference for Sanhedrin 156:13
מאימתי משלם משעה שהכהו וסתמא כרבי נחמיה:
one teaching that if his injury was declared to be fatal, but yet he survived; the other, that if it was judged that he would die, and then the effect of the blow was lightened, [yet he subsequently died — that in both cases he is quit]. But according to the Rabbis [who maintain that in the latter case he is executed], why are two such clauses necessary? — One teaches that if his injuries were declared fatal, yet he survived, and the other, that if they were declared non-fatal, yet he died, — [that in both cases the assailant is free]. But R. Nehemiah maintains that no verse is necessary for the latter case, since he left <i>Beth din</i> a free man.<span class="x" onmousemove="('comment',' A favourable verdict cannot be reversed (v. supra 33b). Therefore in the latter case it is obvious that 'he is quit'. ');"><sup>12</sup></span>