#the smart thing to do after discovering yukari was a spy would be to immediately change his passwords to prevent a security breach

[sage-reads-things]

The fact that Shiodake was already planning to leave everything to Yukari makes me wonder if he was always intending to turn over his secrets. It's never made clear when Shiodake learned she was a mole, but from Yukari's message to him, she suspected that he and his minions knew the truth long before her death. It's possible Shiodake was getting tired of the yazuka lifestyle, and decided to leave all the sensitive information to Yukari because he trusted her to do the right thing with it—whether he knew she was a spy at the time is up for debate, but considering how easily he hands over the information to Kengo without any consideration, this was probably a move he'd been thinking about for a while regardless of Yukari's loyalties. Yukari's death (thanks to corrupt politicians HE helped put into office, no less) simply gave him a reason to speed up the process.