You move and interrupt your aim...

[Calatilla]

There are times when your character flinches and you miscast/fire, and then there are times(especially as a mage) when you start casting a spell, then run around like a headless chicken to cancel the cast, and it still goes off.

[Kincard]

There are times when your character flinches and you miscast/fire, and then there are times(especially as a mage) when you start casting a spell, then run around like a headless chicken to cancel the cast, and it still goes off.

See, that can be annoying too, but at least there's a foolproof way of interrupting your cast...healing.

When you get interrupted unintentionally it's just irritating, and potentially deadly, because the game penalizes you with something like 4 full seconds before you are allowed to cast again.