I think you are confusing travel security with customs and immigration.

As far as I know, when you board any flight in Canada, security is in the hands of CATSA.

Pre-clearance for US destinations is handled by US Customs and Border Patrol and is in place of customs and immigration inspection upon arrival.

There is a potential for confusion in the US because both TSA and CPB are parts of the same agency, but you seem to be getting worked up about something that did not happen.