No the BBC does not constitute a decent source, and also testimonies of DPRK defectors are most often lies due to these testimonies being their only lifeline. DPRK defectors are historically treated very poorly by the southern government and are often under constant police surveilance.

Check out this documentary: Loyal Citizens of Pyongyang in Seoul

By the way, secret interviews from the DPRK, is something RFA likes to do and they are wildly known for the bullshitting campaigns and portrayals of cartoonish evil so any ammount of such "journalism" ought to be heavily criticised.