It shouldn't matter when Iceberg7 got the permanent residence status. Please see quote below from CIC website:
"You are required to provide a police certificate for each country, other than Canada, where you were present for a total of 183 days or more during the four (4) years immediately before the date of your application.
For this calculation only, it does not matter if the absence was before or after you became a permanent resident of Canada. Each day spent outside Canada counts as a full day in the other country."
So as long as Iceberg7 didn't leave Canada (for more than 183 days) within the 4 years immediately prior to the date of application, they shouldn't ask it. I really am surprised why the officers don't get trained in these areas.