[BEAR.]

The kits were banished because of who their father was and Mapleshade's deceit surrounding their parentage.

When Mapleshade was outed, it was revealed to the Clan the father of her kits was Appledusk - the cat they deemed responsible for the deaths of Oakstar's son (Birchface) and Flowerpaw (Birchface's apprentice).

While the code did have some influence over Oakstar's decision, it was primarily because he felt betrayed over Mapleshade's actions. She had led the Clan to believe they were Birchface's kits, and he was repulsed by the knowledge the father of the kits was the cat who "murdered" his son and an apprentice.

If it had been any other cat, it's likely Mapleshade and her kits wouldn't have been exiled .. or at the very least, her kits.