Look at when the ball changes directions, unless Georgie Kelly has a 3ft long neck there's no way its a header.
When you watch the video you can clearly see a boot between the ball and the camera when the ball changes direction, when you consider this with the pictures on here
https://inpho.ie/assignment/hakwm6v0...VEg2XNhbdfg..a you can clearly see that the only part of Kelly's body anywhere near being past the boot is his hand (you can see the boot shadow on his arm and this would have been case by the town/shed floodlight so its fairly accurate and if anything the boot is actually closer to the hand than the shadow shows, the photo is actually after contact with the ball and the other photos show Kelly has a greater momentum towards the goal than the defender so his head was even further from the contact when it occured) meaning that the only part of him that could have connected with the ball to put it into the net is his fist.