He bought it in Canada, I doubt he has much grounds to sue in the UK. If he bought it in the UK, that's a whole different story and he has very strong consumer protections.
I bought in the UK and then moved to Canada. Google refuses to replace the phone (since they no longer have it in stock), and they claim they can't refund me since the payment method I used to buy the phone (an UK Credit Card) is no longer active, and I don't have an UK bank account.
Does the UK have small claims court, and if they do, wouldn't that still be expensive and inconvenient for someone in Canada?
Does Canada have small claims court so, and if they do would they have jurisdiction for a warranty claim against a UK firm for a warranty claim based on a UK purchase transaction?
Or do you imagine this as a person in Canada suing the US parent in some US state’s small claims court for a claim arising in Canada against the UK subsidiary based on a UK transaction?
Because, somehow, I don't think that's a particularly viable option.