Very slightly. They were within a fraction of a point of each other. And San Antonio made the conference finals, so that's a data point in favor of defense mattering a lot.
I agree that the maxim "defense wins championships" is wrong, because you need both offense and defense, but defensive prowess does seem to be very slightly more important than offensive prowess. I recall Zach Lowe saying once or twice in articles that it's a little more common for a great defensive/mediocre offensive team to reach the Finals than a great offensive/mediocre defensive team.