I'm disappointed in the author for writing this in... just another "villain acts like a villain because he's a villain character in the game".
He behaves poorly to predict the future, but the reason why he has that future in the first place is because he behaves as a villain.
The logic is...
In Japan, the penalty for conviction of "aiding suicide or consensual homicide" is 6 months to 7 years. So he received the maximum sentence for consensual homicide, which is not to be confused for attempted murder. Yumezora would have been the one to receive the "attempted murder" charge...