Translation:Marc has an Irish accent when he speaks English.
You're assuming that the system is smart. Rather, it matches provided answers against expected patterns of answers. As far as it's concerned, "Mark" is indeed a typo, which is both true (because people like their names to be spelt as they spell them) and over-literal (because it's just doing pattern matching.
It doesn't know it's a proper noun. It's matching against a set of patterns that human beings have anticipated. There's no actual intelligence checking your answers. This is why you're given the opportunity to submit a correction. Just keep in mind that there's another human being on the other end checking it who's likely volunteering, especially with minority languages, and there's a long backlog of suggestions for each language. And no, provisional acceptance wouldn't be good, as it could end up teaching people the wrong thing.
Also, don't misspell people's names: it's rude.