I think that the apology is good as in it adressess the issue well, it's not often idols actually go out of their way to apologise for this type of a thing so at least that counts in my book, knowing if it's sincere or not is next to impossible though since we don't know her as a person. Also the idea of her getting carried away is an understandable explanation because not everyone comes across that type of language in their daily lives, even if they do know of it and unless you've made the concious effort to completely block the word out of your mind, I think it's very much possible for someone to make that sort of a mistake.