Well, speaking as a [software] engineer...
In my profession, there are certainly certifications one can get, and ethical considerations (as a general statement), although there is no particular licensing. Regardless of these, though, I am employed to write software, but I would not certify that the software I write is flaw-free (nor would anyone else that I know). It's entirely possible that, due to flaws in my work product, someone will lose money, or have other negative outcomes befall them.
If that happened, and my employer blamed me publicly (explicitly or implicitly), I would be seeking large monetary damages, even if the flaw was my fault. My argument would be that I'm employed to write software, not write flaw-free software, and if the company causes me damages (in current or future income) by stating or implying that I did not perform by work duties appropriately, then that is slander, and they are liable. In this case, the "lie" would be to imply that my work product was supposed to be flaw-free, which I never asserted or consented to, regardless of what they desired. Implying that someone is unable to perform one's occupation is textbook slander, and the company would find themselves writing a large check. And yes, even naming the engineer in this context, without strong evidence of gross or malicious negligence, would be cause for civil penalty (imho).
I guess it just comes down to this: there are laws which protect people from having their lives and/or livelihood ruined by false accusation (direct or implied), and implying that an engineer must create a flaw-free work product to be proficient is a false accusation (unless there's a specific contractual obligation to do so, and that would seem suspicious). If I were a company considering this, I'd think twice, and then not expose myself to the obvious liability.