Those details need to be held by a 3rd party though, because if the company goes under, then the code and any critical information may become lost. Executives, employees, and other people might be fired or jump ship prior to any trigger points, so there could be no one that can be held accountable.
The FDA should hold everything necessary in escrow in perpetuity.
Why wait for the company to go under? FDA approval should mandate that the full spec and source code be open source and open to review by anyone, but especially the people in which those things are implanted and all of their medical practitioners. Medicine (and any publicly supported science in general) should never be closed off from public scrutiny.