There's no image of the back but looking at this it looks like there's a black stripe on the back showing through the collar. I've played with the contrast and I can also see another each side of it too so fingers crossed it is authentic! Not 100% sure but looks that way to me.
that’s the first shirt I ever got, it’s now in a frame with my daughters first one, she’s that proud she’s actually got it hanging in her room, can’t ask for much more than that :-)