Hmm, maybe we misunderstood. Sounded like you had a block between the elbow and the Pow Choy (after the turn). Elbow, turn Pow Choy, Chow Choy. Not really all that critical in terms of usage.
"fist punching the sky" (Di Tien Pow Choy) is the straight up punch found near the end of 16 Hands and at the end of Lok Low pt. 1. I don't think an uppercut would fit that description. I really wish we learned the names of these moves.