英语语法高手请进

你的疑问有道理
本句与现在时无关
这里的showing是现在分词作定语修饰the video footage 与所修饰词是主动关系 故用现在分词
后面是现在分词的宾语从句 应该是过去时 如果是现在时 动词应该加s
所以原句应该是showing （that）a old man burst into a hostpital and attacked the workers
burst的过去式还是 burst
相当于一个定语从句=which showed（that) a old man burst into a hostpital andattacked the workers
整个事情导致了leaving four medical workers injured. 这里使用的leaving，是宾语从句中结果状语 与宾语从句中的主语 是主动关系 故用现在分词
是应该理解
a old man burst into a hostpital and attacked the workers with a metal bar and left four medical workers injured.

Police relased the video footage （showing a old man burst into a hostpital and attack the workers with a metal bar, leaving four medical workers injured）.
括号部分（现在分词短语）做the video footage 的后置定语，所以用一般现在时。用汉语理解下，警察调录像，录像显示……
显示的当然是现在时了。