Why did Cairon have to leave right away?

[Locke.]

I missed it last night, just watching his eviction video on youtube and Davina said he had to say his goodbyes right away. Why? Usually they get 30 minutes.

[Tom]

It was announced in the second show. Usually she speaks to the house at 10pm then again at 10.35pm which is when they leave but last night only the once