Actually, I think I can fix this. Ok, we've got something that falls apart and is too mushy. So maybe grinding is out, but we can still chop fine, keep some of that texture. And its still falling apart, but we can deal with that. We just need a few additives, one egg, maybe some Panko breadcrumbs to make this a bit more like a meatball than a patty. Now that will change the texture, but we can safely banish those nasty issues of flowing out of the burger when you bite in. If you can eat Steak Tartar or Carpaccio without fear, this should be easy to chow down upon.

I'm not sure how well it would work, but that's what I see as a possible solution.