This is especially true for the US-Canada land border. Those border agents have a lot of discretion. It's not surprising to me that he had one border agent who rejected him and another who allowed him in. Good for him for trying again, but sucks it didn't work the first time.
can someone give a brief overview of how shipping from Japan works? if I'm in canada and want to order some of this stuff, would I order from the official site or through something like this proxy service mentioned in this tweet?