Yerrr but... Even if the frame does ride like shit, the chap has still learned how to put a bike together and can polish his skills by taking it apart again and rebuilding the parts on a better frame - he'll probably be looking for a frame with track-ends sooner or later anyway.
As long as the frame you have is safe (get someone to look it over if you aren't sure), then get stuck in.
Yerrr but... Even if the frame does ride like shit, the chap has still learned how to put a bike together and can polish his skills by taking it apart again and rebuilding the parts on a better frame - he'll probably be looking for a frame with track-ends sooner or later anyway.
As long as the frame you have is safe (get someone to look it over if you aren't sure), then get stuck in.