This is scary to say the least. In know that all airlines are supposed to keep a record of which agent checked in what passenger but with self checking and online checking this may not be so. As for CBSA, they do keep a recored and you can get it and I think there is a payment to get that record. It will only give the timing of the e form and the date though if my memory serves me right. You will win it because how else could your son get there? Why would he pay for a ticket when this one is on points?