Green outline after using Mocha

There's a fantastic preset included in the presets which combines keylight, key cleaner and spill suppressor.  You could turn off the keylight effect and use the other two effects.  The preset is useful for showing everything in combination.

It looks like you need some matte choking and some edge refinement in Keylight. If you used a keyer (Keylight) for the shot, it's not a Mocha problem. Without seeing the modified properties of the keyed layer, it's hard to point you to a specific solution. Just select the layer and press the 'u' key twice. 

I would probably also add some light wrap to the shot.