You're right PJ2, I was loose with my terminology.
In FAA & Canadian parlance anyway, "enforcement action" is indeed punitive. As you mention, airlines and authorities could instead require additional training without being punitive. From the regulator side often that's accomplished by issuing an "administrative" Letter of Correction, e.g., under FAR 13.11, which isn't considered a legal enforcement action.
Having said that -- when I wrote my original response, in the back of my mind is knowledge that CAAs around the world have been "cracking down" on runway incursions and there is sentiment among CAAs that punitive enforcement actions may indeed be an appropriate response for the most serious incursion events.
In part this has been done to "raise the profile" (visibility) of runway incursion violations, i.e., to "send a message" to pilots and ATC that certain violations will not be lightly tolerated. I don't necessarily agree with this approach, just reporting what the trend has been over the past decade.