So, it appears the end user has been delegated as the final tester of the product......
Welcome ... to the real world!
Sure, we are all testers. Even with the resources that Canon has, it is not possible to test all combinations, all possibilities, all firmware setting, all shooting situations. How many combinations can you imagine up?
This is not just Canon having a problem - everyone in the electronics/software businesses (and since cameras went digital, they're practically a computer) has this. And then think of the guys who have to test for interoperability with other vendors, whose products have idiosyncratic bugs but YOU have to work around, 'cause "they are big guys, so your design must be wrong".