Because... Shadow and Eggman are not on the same side of the coin anymore. Stop call their relationship "Neutral". Shadow roundkicked Shadow in the face. That Shadow who took the kick in the face is one of Infinite's clones. Infinite is under Eggman's army, as its commander. Therefore Shadow that kicked the faker is against Eggman.
Also, we are talking about NOW! Not past, not future - NOW! Therefore, Shadow is against Eggman and his squad right now, making Eggman being an enemy to Shadow.
And last, I don't have a power to lock that article - I asked Ultrasonic to locked it to prevent it from suffering the Edit-Warring. If it's unlocked and you went back to change it, you will suffering more than lost a right to editing. Yeah, that's called "Spam", and the admins don't like it.