Nick,
Not sure why you're seeing that. JLinked uses the "formatted-name" value from LinkedIn which, according to their documentation, should return:
The member's name formatted based on language
That should have the full name for the user (or at least we've never heard of it being otherwise). Now that I look at the documentation though, it may be possible that the user has chosen their formatted name to be something different.
Have you tried with more than one user, or is this only happening with a specific user? Worse case, we can help you easily change our code to switch from formatted-name to "first-name last-name" to at least test that.
Thanks,
Alex