I've never dealt with copiers in Feralheart myself, but if it did happen I would most likely shrug it off and think it was a coincidence. (Unless it shared like, every single feature of the character including the name or something)
In your case, no, you shouldn't be able to copy someones character directly like that. Inspiration isn't the same thing as copying. Being inspired by characters and making your own, new thing is great! Asking if you can completely copy someone else's character is, well, not great. Even if you like someone's character, that doesn't mean you copy them. It just makes you look like you have no creativity of your own. I'm sorry that you had to deal with somebody having to ask that, just remember to politely tell the user no, or to even offer some tips on creating characters theirselves.
On the topic of copying characters, I thought I should bring this up. You can't really get upset if someone has a character similar to yours, though. I've seen a video where someone has been reporting and putting out screenshots of Feralheart characters and their usernames because they have a resemblance to their character which 1. has a very common look and color scheme and 2. uses the default markings, which EVERYONE who plays Feralheart can use. If anybody sees a character that maybe has a similar color scheme to your character, or has the same markings, remember that you do not own the markings. They probably aren't even aware of your existence, so never jump on somebody and yell at them for 'stealing your character'. I've been called a copier before, the day I joined Deviantart since somebody happened to have a character with a scar and dots under their eyes just like I did, and they accused me of stealing their character. Even though I had never seen the character before, it made me feel bad, and that I had done something wrong. Don't make people feel like this! If someone has a character like yours, just ignore it.
Sorry for the huge paragraph at the end, but I just had to say that. There's my opinion on copying.