I'm currently dealing with a small claims debt collection case (so, admittedly, way less serious and devastating than a criminal trial for a felony). The debt collector and their attorney habitually engage in "sewer service", and in my case, never actually served me. They say they did, at an address I and no one I know has lived at for years, to someone that they say is me (the "me" that's half-a-foot taller and 30 pounds lighter). Completely different county from where I currently live and work, too.

State laws say that the case should be dismissed, and that the debt collector can refile and actually serve me. Not a single attorney I've talked to (if they'll talk to me at all) has said that a judge will actually do that, though. Screw what the law says; evidently, they have the leeway - and generally do rule - to simply say that showing up to defend against the case cures the service issues.

It's all been a bit of a revelation. I call bullshit on judges who say that their hands are tied by the law. What's actually happened is that quasi-legal judicial norms have developed over time, and what they're afraid to go against are those. It is, of course, pure happenstance that they feel obligated to throw the book at criminal defendants pleading sympathy (because otherwise they'd be getting in the way of the careers of fellow legal professionals, the prosecutors) while ignoring civil defendants begging for their constitutional right to due process be affirmed (because otherwise they'd be getting in the way of the livelihood of fellow legal professionals, the debt collectors).

While looking into "sewer service" I found an extremely foul supreme court case: https://en.wikipedia.org/wiki/Rotkiske_v._Klemm Knowingly serve somebody at the wrong address, acquire default judgement, statute of limitations expires before they even become aware of it.