Both are valid dialect, though - the first is really just an accent thing (ok, it's a really inarticulate sentence, too, far too many 'thing's in there, but I guess that's not what you're complaining about?).
And yes, 'we done' is perfectly normal dialect. Granted, this student should be trying to speak Standard English with you (as s/he will, in future, with bosses etc), so on those grounds, this isn't really correct. Do they use Standard or Dialect when making verbal presentations? What happens in job interviews?