Dodge while using frost bomb

If you dodge while trying to cast Frost bomb, it goes on Cooldown, and it doesn't appear. Not sure if a bug or if the cast time is just interrupted but counted as it being used, so it goes on cooldown.

I've noticed the same, sometimes even when just walking and trying to cast Frost Bomb.
Another issue with Frost Bomb is, that it is, esp. in maps with a lot of obstacles or different terrain heights, difficult to cast it on monsters. It seems to need a free line of sight from the character to the monster and if there isn't, it simple casts Frost Bomb at the feet of the character (so fully useless).