Why monster memory doesn't always display xp for killed monsters?
My ratling elementalist encountered a hydra in the wilderness and killed it easily from afar. I wanted to check the monster memory for experience gained only to find the information missing? I thought it might be a bug or something since I leveled up right after the kill, but then I checked some other single kills and while most of them do display experience average, some of them don't. Why? Is it random? Every other information about the hydra I could get from killing it with spells, i.e. HP and speed, is there, so why not the xp?
Screen: http://i.imgur.com/H5SYXAD.jpg
Gate closers: GE Wizard, DE Archer, Ratling Elementalist, Ratling Duelist, GE Merchant, ME Druid, HE Mindcrafter, ME Monk