Sorry to hear this
@Barry Tetra
I have no personal experience of this. I've heard of females dying during mating if the male has been aggressive towards her etc, but never from their spine snapping during wrapping. It sounds as if this female in particular was weak and that it's just rotten luck. You can remove the eggs from the tank and place them in the nest yourself, providing they're fertilised, but the chances are that the male will eat them when they fall rather than put them back in the nest. I'm guessing it's his first time spawning and he hasn't quite got the hang of it, may be how the female got injured if they were unable to wrap properly.
Going forward, you're best off to place the male back in his tank and re-condition him while conditioning a new female or try a new male with a new female after conditioning them for atleast two weeks on live foods, little and often.
Sorry it hasn't worked out the way you've hoped, mate. There's always another time. Sounds as if it wasn't your fault so don't be hard on yourself about it, just unlucky