A few days attack for a hex is too much, IMHO.
Also new there are a few ways to avoid new rule. For example:
1. Being invisible (yet admins don't do nothing about it and invisible players kill low levels)
2. Exe can pretend he/she had order to avoid new ruile by simply asking a friend to make an order. This can be done in clan chat, ally chat, in skype, on face book, by phone etc. For example: lv 18 magmar exe doesn't like what I say on forum, guards don't consider it a provocation so lv 18 can't attack me for that, so he tells his friend on skype "Please tell me in game you want me to exe Fox Face" and friend tell him "Please exe Fox Face" so lv 18 exe kills Fox Face, and when guards ask to prove it's an order lv 18 shows them chat log of his friend saying "Please exe Fox Face" and guards can't do nothing.
Answer :
!.Invisibility buff works only on neutral and own race territory, so if a invisible attack you, you may should think twice about what you did.
2.If a high level do that just to have the right to exe you, there is two options :
1.You did something to him, so is your own fault.
2.He is a pretty bad guy, in any rule there is alway some way to jump on.
P.S. Invisibility price is not that low, so i dont think high level would be that intrested into just kill low level for fun and waste that ammount of money.