The geometry just doesn't add up for that to be where his hand really was. I call it the "Rubberman" photo. I did a little analysis on that photo. Look at the photo below. You notice the suit of the grandfathers left shoulder isn't creased ( plus the seam in the shoulder is perfectly straight) - indicating that his arm isn't bent. That would put his elbow at about the same place as the red dot. Now the yellow line shows from the shoulder to the elbow and the elbow to the wrist. If you were to straighten out that line, he must be "Rubberman". His arm would go past the left shoulder of the grandmother !!!
Here it is with the arm extended to the correct length :
Zoom in on the grandparent picture and tell me who’s pink finger tips are grasping typical white granny’s left elbow.
Look at grandpa left hand and his right hand, the first finger of both hands are of the same person, that's all I am saying. I don't know where they got the photo of the floating hand but it does look like grandpas hand.