I grew up doing wildlife/exotic rescue and have handled maybe half a dozen rehab/pet squirrels that could be considered domesticated. The ones around my house are my yard pets and they're used to regular interaction with me. I've never been able to just pick one up. To be as passive as this one was is such a bad sign. On top of whatever injury/illness it would need to overcome, it's going to need dedicated syringe feeding for extreme starvation/dehydration. I'm hoping for the best but even euthanasia would be a better outcome than what awaited it. It's definitely never returning to the wild at least.