Break the slab completely, epoxy it back together, polish, and forget about it. It will be inconspicuous and stronger than the rest of the stone.

Aww Juno what a letdown - I don't have any advice but wanted to say chin up, they'll figure it out.

Treb I've always been curious about this - does epoxy yellow over time? Will they be able to see the repair after a few years?

"Treb I've always been curious about this - does epoxy yellow over time?"

Only if it were a wide line and exposed to direct sunlight for extended periods. There are UV proof adhesives available.

Will they be able to see the repair after a few years?

No.

Fabricator promised to discuss with me today but sent an email at the end of the day and pushed me off till Monday. They didn't want to show me the cracked slab, and I now suspect it was a bigger oops than they want to admit. I'd be ok with a good and clean repair job but there must be some reason they are not suggesting it?
Not sure how to move this forward, any advice?

Yikes. I'm sorry to hear of the mishap-especially when you have been waiting for so long on seeing it installed. I would ask them why they don't want to attempt repairing it. But, I wouldn't push it becoz I wouldn't want it to become 'my problem' at the end. As in if as professionals, they can't take responsibility for the product they install, I wouldn't want it used. Can you use the broken slab for the perimeter base and the new slab for the waterfall(swoon!) islands?

I think I'd insist on seeing the cracked slab if for no other reason than to confirm they cracked it & didn't give it to someone else. Also, letting you worry about it until Monday?

Insist on seeing the cracked slab. If they won't produce it, move on.