he has three hands, because his fight scene with Mara describes his use of a third hand to pull the dart out of his belt that killed her.
Either he had three hands (One holding back her dagger, one holding onto her hair, and then it says "with his other hand, he struggled at his belt for a dart."😉 or Mara is still alive and Caedus never existed.
Lame writing, but it's canon.