I don't know exactly where on the neck he's placed the scale pattern, but we now know that the notes in the chord are a 6th apart and in G minor. So the easiest way would be to place the G minor pattern lower on the neck (or anywhere really) and you have 7 tries to find it. Start with G and Eb, then try A and F, then Bb and G, C and A and so on. Then, like I said, you have 7 tries to find the right one he starts on! Using the process of elimination, on the 8 degrees in a scale. Of course, you wont find it unless you are in the same position as he is, and shift to the same position he did, but I think you may be able to find something that sounds good in doing this all the same.