Ezreal Mystic Shot bug

I play ALOT of Ezreal and I noticed that if an opponent is in melee range of Ezreal and he lands his Mystic Shot all his other abilities get the 1 sec cool down except Mystic Shot. It seems to be because when you fire it the skill doesn't go on cool down before the hit lands so it doesn't get the 1 sec knocked off. This is most noticeable in the jungle when camps like wolves that get real close. This is not a once in a while event, it seems that opponents have to be at a range of 50 or this happens every time.