Well, in 5-6 months it is not inconceivable for him to put on 20-30 pounds if he is new to lifting. I only gained about 15 because of my poor training regiment with machines when I first started

I wish I knew what I know now when I started. I would of probably seen gains like crazy at first. Anyways, I have a friend who was 160, and went to 190, but now he has leveled off. At first I thought he was juicing, but not now since he leveled off. Now if my friend would of continued to gain and got up to 220 after 9 months to a year..then I would think he would be juicing.. but no way to tell for sure. I'm sure you already pondered my theory and know this stuff, but what the hell I'll add to my low post count