Board Thread:Speculation, Theories, and Rumors/@comment-6858788-20141218003512/@comment-679780-20141218180125

My guess Knuckles will put his friends first before his duties because while he is no detective on who stole the Master Emerald, he is usually close with the usual suspects anyway such as Rouge and Dr. Eggman who are the only two with the technology to go up to the stratosphere. Plus a giant island falling from the sky isn't something you'd miss (unless you're an archeologist in Mystic Ruins) so if Knuckles was away from his post he would soon find out about the falling of Angel Island and pursuit the usual suspects.