I can answer the question, with your permission.
I would like to clarify the way in which tax collection agreements work. The Canada Revenue Agency estimates the provincial tax base in order to estimate the money due to each province. The money that goes to the provinces is based on an estimate of the taxes paid. If taxpayers do not pay those taxes, the federal government takes on that debt.
In return, the federal government keeps the money from penalties and interest on the unpaid debts. The reason is perfectly logical: because the provinces receive the full amount based on the initial estimate, the federal government keeps the interest and penalties to make up for the costs of its collection activities.
I don't know whether that answers your question, but I feel that it clarifies things.