It wouldn't surprise me. Federline could be tested but he's probably been advised by an attorney to stay clean. There's a lot of money riding on this. As for his hair, he keeps it so short there wouldn't be enough to find anything. When he appeared on RAW not too long ago he had almost no hair at all.
I guess they could always take hair from another part of his body. I just think its a shame that the children have to suffer. I often wonder why these stars have children when they lead lifestyles that shouldn't include children. I just don't see how you fit being a full time mother in with being a full time star and party girl. You can't...IMO ~P~