The ship teams

Hi,

In this mission you need to separate two teams, the first team has sailors older than 40 and younger than 20 and the second the rest.

Now I get a faulty result here:

Your result:[["Dow","Richardson"],["Carlos"]] Right result:[[],["Carlos","Dow","Richardson"]] Fail:two_teams({"Richardson":20,"Dow":40,"Carlos":34})

According to the description of this mission my result should be the right result, any ideas if I'm overseeing something or this is a mistake in this mission?

Thanks in advance.