Utter nonesense to think its been done to save Perez. As someone mentioned above he is just about the only person that would be safe now in a 3/4/5+ HM being up scenario.
BB operates a positive voting system (vote for the one's you like) as opposed to negative system (got for the one's you hate) to make sure controversial characters are kept in as long as possible. In a negative voting system Perez would have zero chance of staying. In a positive system he's likely the first to be safe. At the bottom of the voting pile are people we can't even recall are on the show (Kav, Keith, Patsy etc.).