That's how it used to work, and that is the way it works now. The change was put in place to correct for the fact that under the previous legislation the reduction in the public sector benefits was more than warranted by the CPP benefit that the employee received. Just to use a very simple example, if one were to receive a $10 CPP benefit, the previous legislation had the effect of reducing the public sector benefit by $11, so we corrected that.
On November 20th, 2007. See this statement in context.