D800 focus with 1.4 prime lenses is very variable and inaccurate

Personally I think shooting hand held at 1.4 when there are two possible areas of movement, the subject and the photographer is going to lead to inconsistent results, I have not seen many children who remain static when held in an adults arms plus the movement of the photographer when pressing the shutter release. When I received my 85 1.4 I was keen to see the background qualities, I found a discarded sports bottle ( a static subject ) I had no tripod with me so to try to allow for my possible sway I shot at 2.5,  the camera acquired focus but my movement was enough to shift the focus point, you could actually see the distance point of focus and by how much my movement has shifted it from the intended target, I would estimate at f 2.5 the zone of acceptable focus was no more than 2.5 inches, at 1.4 it would be less ?