Would that even be legal? The company has obligations to its creditors and shareholders; simply giving away potentially valuable intellectual property right before going under seems to violate those obligations. And it's the sort of violation for which someone might be personally held liable.
I'm not claiming that a company can never open-source anything, but rather than they have to have a plausible business case for doing so. And I don't see a plausible business (as opposed to humanitarian) case here... But I'm not a corporate lawyer, just someone interested in this sort of thing.
Edit: there's also the FDA to consider. If you make medical devices and you want to release the source code, you probably need to demonstrate that it's safe for users to reprogram their devices (and it's not safe).