Tiberius said:In the PHB it says the Shield spell provides cover. The Sage is saying that the spell provides a cover bonus to AC. A subtle though significant distinction. Accordingly, the Shield spell would provide a +7 to AC, but would not confer the bonus to reflex saves nor the immunity to AoO inherent to 3/4 cover.
Context is important. The Sage gave this answer in response to a question on what sort of AC bonus the shield spell provides -- in particular, whether it stacks with normal armour. The question wasn't about the other bonuses provided by the spell, so naturally the Sage didn't mention them. See p.35 of the D&D FAQ, somewhere on the Wizards site.