Amazing powers of deduction wouldn't have been needed to figure out that would be his response. The expression on his face, his posture, he wasn't in the bar to be social and have a good time. The fed was miserable about something and decided that alcohol was the best way to rub it out. He knocked back the glass of whiskey that had rested at his elbow before he answered.
"Guy sees a familiar face and he has to come over and see hello," he replied as if it was the most obvious answer in the world. "You look like you could use a friend." Not that he gave a damn about that. He couldn't care less what problems had settled on Booth's shoulders and led to him visiting the bar. It was only partly because he resembled someone Lindsey could barely stand.
"So what happened? You lose that chair you had your eye on? Someone with seniority pull rank on you and pull it out from under you?" His expression became one of mock sympathy before he turned to the bartender, raising his hand and motioning to the empty glass beside him.