I just worry that you're fretting too much about it, and reading too many opinions of others might make it worse for you. Be optimistic. They have nothing to lose at this point, caution is fine, but like I said, I doubt years will be added, unless AK loses her other slander case.
Besides, how can RG hurt them? He's already put RS at the scene and said AK was outside.
What's he going to do, make up more stuff? If he does, then the defense will need to call more witnesses, or pull more evidence into question to counteract what he says. He can't keep making up stuff or he'll make up one too many things and slip up. I'm certain he doesn't want to overplay his own hand. You might believe somewhere in your heart that these two helped RG. Otherwise, I don't see why having RG on the stand is not making you do cartwheels. I am.