And when he discovered it later, he erased it without a trace.
If you look at it that way, it fits the puzzle.
The jerk killed Team Leader Oh and stole the recording,
and when that failed, he targeted the broadcasting company.
including the reason, it explains everything.
Then are you saying Team Leader Oh's death wasn't an accident, aren't you?
It seems so.
And since they haven't gotten what they wanted, it isn't over.