The tape records the conversation between Yan Chen and Qiu Tu on the night Jia Shu died.
In the conversation, Qiu Tu clearly warned that Jia Shu might be in danger, that Liu Xiongyuan might be preparing to ambush him.
He suggested that Yan Chen go to rescue Jia Shu.
But.....after hesitating, Yan Chen chose to abandon the rescue, didn't even warn Jia Shu.
It was precisely this decision that led to Jia Shu being taken out by Liu Xiongyuan.
Because the recording was secretly made, and it's impossible to confirm whether the two voices really belonged to Qiu Tu and Yan Chen—it could be just two people with similar voices—it can't be used as real evidence.
Even if, given the status of Huang Shangzong, Liu Xiongyuan, Yan Chen, and Qiu Tu, the recording could actually be admitted as evidence, it wouldn't make a difference.
At their level, the life and death of an ordinary person without any status in the planning zone doesn't really count as a big deal.
