I believe he said that the sequester would slow budget growth over a ten year period... which is technically true, since the sequester calls for $1.2 trillion dollars in cuts in discretionary spending over 10 years (split evenly over the 10 years, requiring $109 billion per year reduction), but the sequester does not stop all growth in spending over the next decade. It only cuts discretionary spending, not mandatory spending (for example, the sequester only cuts Medicare by 2% and doesn't effect Highway Trust Fund spending or Department of Veteran's Affairs, among others). Discretionary spending is currently just above the historical average since 1972, but with the sequester will become lower than it has been since 1970 by 2017 (and you'll note the country has grown in various ways since 1970).
For non-military discretionary spending, it's an estimated 9% to 12% cut across the board this year. For 2013, sequester cuts are required to happen at “program-project-activity” (PPA) level... which makes limiting the negative effects more difficult. Discretionary non-defense activities that may be affected include air traffic control, border patrol, scientific research, NIH, Food and Drug safety, special education, etc.
So, given what a blunt instrument the sequester is, how little time there is to plan to minimize its effects, and how little wiggle room is available, calling it just a "decrease in rate of spending" seems like a dangerous oversimplification. And that's ignoring its effects on the still fragile recovery as well as the follow-on effects of delaying needed infrastructure upgrades and investments.
A sequester overview is available from the Bipartisan Policy Center here