It is written but you are ignoring the comments.
Entering Canada
When you arrive in Canada with Can$10,000 or more in your possession, ...

Leaving Canada
When departing Canada by air with Can$10,000 or more in your possession, ...
Take a look at the declaration instructions: http://www.cbsa-asfc.gc.ca/publicati...s/e311-eng.pdf

The first paragraph plainly says that each passenger is responsible for his or her own declaration. (soon to be its own as well)

What else do you want people to say. The Border Security shows you watched is for USA crossing and I personally saw Canadian version where they were adding the sum per person. Certainly if each person on the declaration form has funds under the limit, no explanation is asked for by the agent. They normally will ask you again; then just tell them what each of you have individually and that would be considered a full disclosure and no penalty if you still are unsure if total or per pax is the rule. Crossing the USA, its definitely per declaration card.