He knows as well as anyone about the 5 year hueristic (length too long to be meaningful), so he's trying to say "over 5 years", but still hold onto the sense of "meaningful estimate". My sense about Sam is that he trusts his PR instinct to be usefully manipulative enough that he doesn't think he has to plan it carefully in order for his statements to be maximally opaquely manipulative. (He speaks cleverly and manipulatively without a lot of effort.)