Who's tougher? My old man or, your old man.
Actually Transport Canada is a lot tougher than the FAA where aircraft certification is concerned. The FAA will certify a foreign built aircraft based on the certification criteria of the country of manufacture. (Mostly JAR countries). In the case of the A-310 the FAA performed some route proving flights and checked the aircraft for general handling qualities and approved the A-310 for use in American airspace. The FAA for a long time would approve a derivative aircraft by only testing the differences between the new design and the original design no matter how many derivative aircraft designs here were. The A-310 was originally designed and certified to FAA standards, which required an FMECA for all systems. This was at the system level but to get Transport Canada certification the FMECA had to go to the smallest piece part level of every component in a given system, which was much more stringent than the original JAR requirements.
Bombardier tried to certify the CL-604 design based on previously approved versions of the same aircraft. This is based on the FAA and their method of certification. Transport Canada said no and made Bombardier perform the product assurance analyses down to the piece part level just as was done on the A-310.
I assume this also applies to helicopters as well.