Being born in the wild is not really and exemption, just a marker. Clarity, especially in cases like this, in determining when something has gone wild is tough.   Being born in the wild just shows a clear break from domestication.  Perhaps being "wild" for a year (surviving the winter), without human support, could be another way to measure.  Just a interesting point; you used the intent (irresponsibility) of someone releasing something to determine if it's invasive.  "Irresponsibly" might be a pretty subjective measure for defining feral, invasive etc.  Interesting issue, especially if we continue to see mild winters.