It IS a litle different when you start off with a tribe of 5, you have to be really careful who you get rid of. You never know when a merge is coming especially when the show seems based on ethnic tribes. To throw a challenge with only 5 members abd its to get rid of a big guy is stupid. If anything they should have tried to motivate him. I remember StepheME's first time on Survivor they didn't merge until her tribe had 2 people left in it.
I agree it is very stupid to throw a challenge. They should have kept trying and IF they ever lost, then they could vote out Billy. Things like this can come back to haunt you.