Ghost is one calculating assed dude...and when Tommy got out it seemed like he knew the plan all along because he mentioned to Ghost how Angela was all fugged up when the lawyer brought up the fake sketch to get him off. Tommy might be a wild out cokehead at times, but Ghost knows that that's the only dude he can trust to have his back, and that is his boy and nothing's going to break that bond...he's been telling Angela all along that he wouldn't testify and now he told her "You can't have Tommy"...
Plus, last episode when Kanaan wanted to go to the meeting with Lobos and Tommy eyeballed and him and said he was good...Tommy is going to be the point man when they set Kanaan up for a fall...wouldn't be surprised if Ghost and Tommy flip it and tells the Serb that Kanaan and Ruiz set all that heist shit up and the Serb takes them out because of it...

Plus, last episode when Kanaan wanted to go to the meeting with Lobos and Tommy eyeballed and him and said he was good...Tommy is going to be the point man when they set Kanaan up for a fall...wouldn't be surprised if Ghost and Tommy flip it and tells the Serb that Kanaan and Ruiz set all that heist shit up and the Serb takes them out because of it...