Ghostblade Bug

is bugged with teleport. I was playing graves top and we were about to end by destroying the enemy nexus. I popped and auto attacked about 3-5 times and then I teleported to a minion. Next thing I know, was off cooldown and yes it did let me click and yes the effect went off. So basically, teleport let go off cooldown and allowed me to activate it again only after about 10 seconds from my original activation of it and then teleporting to a minion.