Example: Cast Obvious Fireball Wild Magic turns you into a carrot Right click somewhere again, another obvious fireball, who'd have thought
Sounds like an issue with the random polymorph abilities. If you don't have to use an activated ability to polymorph, whatever your last active skill was will still be in the cued up, so you can still right click to use it. A minor bug, since only Wild Magic and Demonology currently polymorph you at random. But yeah, someone should probably look at it...
Interestingly, the reverse appears not to be true. If you use a skill available in polymorphed form, you willbe unable to use it when the polymorphed form ends, even if you don't map your right click to some other item or ability.