Why are wireframe lines green in object mode?

What does it mean when the wireframe is green in object mode and looking at it in wireframe mode?

I dowloaded someone else’s model and when I opened it I found the wireframes were green and could not be edited normally. Something really weird is going on here. The model was made using a process I’ve never seen or something.

This is the model: https://www.blendswap.com/blend/16684

Hey, It maybe part/all of a ‘group’ - check that