No he didn't switched sides.. He's still doing the mission. I think he's gonna watch over Hajun's dad..(･–･) (･◡･)/
If I remember correctly, his actual mission was getting information about Professor Park and, if it gets so far, killing both, son and father. Or at least capturing them. Now that their agency basically betrayed them, it would make more sense for Candy to switch sides and watch over Hajun's dad. (≖_≖ )
I'm not really so sure about what I've said tho cause the raws i read was not a complete chapter
Maybe Candy switched sides because Hajun's dad, Professor Park, is actually a good man with no ill intentions and was only used?