this seems to bother you more than us. I'm making stuff up, but here in America, our narrative is "it's good to kill the naughty word." It's doesn't hold up in court as often as we'd like (too many women are wrongly convicted in their self defense cases).
But you can bet her lawyer is going to plead not guilty and cite how she was scared for her life, especially after:
he threatened her in public after she outed his affair
he assaulted her in the hallway by slamming her into the locker
he stocked and stole her diary
in violently interrupted a school dance to out her
he one-punch KO'd the only person who tried to defend her (and those can be lethal)
No adult rushed in to stop this, creating an environment of fear and that everybody sided with him once he attacked.
Ladies and gentleman of the jury, anyone can see the writing on the wall and we can only thank god that his hand came down and struck first before anymore harm came. You must acquit this young lady.