If KR up until the time JRN died, had 100% custody of their son, he would have received whatever family allowance was issued by the government, and would have had to pay nothing to JRN. If JRN suddenly was awarded 50% custody, I believe that would mean that any family allowance benefit would have gone to her, or been shared 50%, and that KR would suddenly have to start paying child support to 'equalize' JRN's income. That is how I have seen it work here in ON, and I believe the laws are the same in AB. If KR was set to begin a new job, depending on his wage, he could have been thinking he'd be making a pile of money, and then discovered he'd have to start giving half of it away. That could be a big blow, if he wasn't aware of the financial implications such a change could make?