![Iron Fist mistake picture](/images/screenshots/291000-291999/291927_sm.jpg)
Continuity mistake: When Danny and Ward meet Joy in her new place, Ward says "who was it who said I was being childish?" Danny is in the background, holding the folder cover open with his left hand. Shot cuts as he speaks, and his hand's suddenly on the pages with the folder cover hanging down loose.
Answer: In the comics Iron Fist is able to use the power on both hands. There is no reason why Danny shouldn't be able to. Presumably he chooses to only use the one fist at a time, focusing all his power into one hand rather than distributing it between 2.