When i rapidly cast 6 spells on rotation in wereraven form i randomly reverted to normal, its not at any specific time its anywhere from at first cast to half a minute of combat.
it does not happen when i remove 1 of the spells (ice spike) from the rotation.
Spells used: Ice Spike (from item), cold snap, olexras flash freeze, bonechilling cry, ice talons and trozans sky shards.