虚拟语气时态退一格,打破窗户在过去,所以退成过去完成,好像没什么问题吧。
不过生活里口语的话好像did it 也一样
as if既可以用与real也可以用于unreal
比如
时态一致:he looks as if he' knows' everything=based on his look, I think he knows everything
时态退格:he looks as if he knew everything(but he doesn't)
而根据你的前后文,这里是unreal的,所以要退格