I haven’t watched the video/series, but here is something to know. bone shapes are easiest to create when you think of it this way. Create them from top view. The origin(0, 0, 0) is the head/root(I don’t know which term is used in the video) of the bone. 1 positive unit(Meter by default) on the Y axis is the tail/tip of the bone. so if you go larger than 1 unit it goes past the tail. if you go below the the X axis then it move below the head. the other axis align to the bones axis. Also note that any transforms done in object mode are not used in aligning the shape.
