The plausible situation is no criminal case, just a civil case, and probably settling for what amounts to a fine / delayed purchase, e.g. the "$10k donation" alluded to. But the worst case possibility, even if very unlikely, should include jail time (somehow -- I too don't know exactly how that would work out or who exactly would go to jail, manager or dev).
Just curious here... It's a license violation, then, not a copyright (law) violation. So isn't it more like breach of contract, i.e. a civil matter between parties, rather than a criminal case? And one does not go to jail for civil cases, do they?
GPL is a license to use copyrighted code, not a contract. If you violate the terms, your license is revoked. If you then continue to distribute the code in question without a license, then you may be liable for copyright infringement.
The first consequence of this is that only the copyright holder has standing to sue you, not anyone else who thinks they have a right to your code because you violated the GPL terms. They’re just wrong.
The second consequence is that the only remedies for copyright infringement are an injunction and damages related to the copyrighted code. So a court could force you to stop distributing the copyrighted code, requiring you to either (1) remove the GPL code from your product and use a substitute, or (2) pay for a commercial license from the owner. But you would not be forced to release your proprietary code under a GPL license.
Regarding jail for civil cases, no. In the US, we eliminated debtors’ prisons many years ago.
