I think it is convenient, but BB needs to step the game up, here are my thoughts:
1. Sam was chosen as a HM out of thousands of applicants, there must be a reason why, maybe BB are banking on Lesley going and giving Sam a chance to shine.
2. BB was beaten by CLI in the ratings last night, BB are panicking as Friday is also CLI's vote night, they needed a twist to bring in the viewers.
3. The promise in the pre BB adverts "What happens, you decide" seems to have been forgotten, this week we truly are deciding.
4. BB has a script and a favourite HM and they will bend the rules which ever way they want to make sure this HM wins.
Four theories - which one is right, you decide!!