... there have historically been two approaches to examining the nature of time: "Reductionism/Relationism with Respect to Time", and "Platonism with Respect to Time". In the first, time does not exist outside of the events (i.e. changes) that occur in time. In the second, time exists independently of whether or not anything actually changes.
So while it is possible to state that God is "outside of time" in either system, the phrase will mean different things depending, not on your view of God, but on your view of time.
If you hold to the "Platonism" approach, then you are stating that God exists outside of space-time, and so he sees all things in his eternal Present, whether those things are past, present, or future... This kind of knowledge is called the "science of vision".
On the other hand, if you hold to the "Reductionism" approach, then to state that God is "outside of time" is the same as stating that God is not subject to any sort of change (as, in this view, time is simply the measure of change).
Notice, though, what the two meanings of "God is outside of time," based on two contrary understandings of time, are. Setting aside what Fr. Dowd writes about the "science of vision," we have:
God exists outside of space-time.
God is not subject to any sort of change.
These two statements, unlike the views of time from which they derive, are not contradictory. In fact, if (as I think everyone agrees) change implies time, then essentially they imply each other.
In short, the Reductionists and the Platonists mean equivalent things when they say, "God is outside of time."