bug with bow equipped mobs

[Asherosthar]

Hello, here seems a bug with mobs who use bows.
When i use areaattack all of them fight me, but when i kill first one, they stop fight but....

 l
A hallway in the castle
  The hallway is glittering with adamantite and various paintings from
around the world. Torches line the walls making your shadow seem to
have a life of it's own. To the east you see a wooden door.

[Exits: north south]
An obsidian guard is here, fighting YOU!

<585/633hp 102/437mana 221/251mv 154068tnl | NS> sleep
You go to sleep.

<585/633hp 102/437mana 221/251mv 154068tnl | NS> wake
You wake and stand up.

<585/633hp 102/437mana 221/251mv 154068tnl | NS> l
A hallway in the castle
  The hallway is glittering with adamantite and various paintings from
around the world. Torches line the walls making your shadow seem to
have a life of it's own. To the east you see a wooden door.

[Exits: north south]
An obsidian guard is here, fighting YOU!
 
It happens only when they are blinded.