in a split-second 電光火石間

in a split-second
繁：電光火石間
简：电光火石间

昨日（1日）荃灣衝突中有警員開實彈，一名中五生中槍穿肺，警務處長盧偉聰其後稱警員是「生命受威脅」及在「電光火石間」決定開槍，認為合理及合法。

【十一．示威】荃灣開槍事件目擊者：示威者靠近前警員已拔槍　質疑何不向天開槍（2019年10月2日）。明報，取自https://news.mingpao.com/ins/港聞/article/20191002/s00001/1570014925611/

Meeting press late on Tuesday, Police Commissioner Stephen Lo defended the officer’s move, saying he gave a warning.
“My colleague was under a close-range attack. He made a decision in a split-second because he felt his life and his colleague’s were being threatened,” he said. “We believe [the action] was reasonable and legal.”

18-year-old shot by Hong Kong police in stable condition as students stage protest. (2019, October 2). Hong Kong Free Press. Retrieved from https://www.hongkongfp.com/2019/10/02/18-year-old-shot-hong-kong-police-stable-condition-students-stage-protest/