a momentary slip with serious consequences; a wrong decision made in a moment of weakness; a wrong thought on the spur of the moment
? 你總不能因?yàn)椤桶衙疾灰耍?高云覽《小城春秋》171) Surely you’re not ready to die just because of your momentary slip?
一念之差yī niàn zhī chā
差：錯(cuò)。一個(gè)念頭就錯(cuò)了。形容因自己一時(shí)的疏忽或考慮不周，而產(chǎn)生嚴(yán)重的后果。a momentary slip, a wrong decision made in a moment of weakness, a wrong thought on the spur of the moment