Theory:Torchwood television discontinuity and plot holes/End of the Road

Does the Null-Field Generator work on Jack?
Did Jack notice that when he bent down to kiss Angelo, all of his wounds healed - since his immortality would no longer be cancelled by The Miracle's Morphic field? For that matter, could Jack and Esther use the Null field generator to cancel the Miracle and to heal Jack's gunshot wound (at the end of the episode)? Unless Jack was wrong and it wasn't the Morphic Field which canceled Jack's immortality - then the generator couldn't protect him.

The generator does work on Jack, as we saw that Rex could not hear what Jack was saying when he stepped outside the field. I don't see how this is a plot hole, as it's just being proposed that the generator could be used to heal Jack -- if that does occur, it will happen in a future episode. Why's it being discussed as a plot hole in End of the Road?