Mr Average.
I think you have too many assumptions there!
Your Canadian friend would need to look at his own licence and see if he's allowed to fly under IFR on that. There isn't much point in the UK allowing a UK pilot to fly under IFR in VMC, if his Canadian licence restricts him to VFR.
Also, French regs are difference to the UK. I don't know much about them, but I believe that they do allow at least some VFR at night. The IFR at night on a PPL is a uniquely UK solution as I understand it.
dp