I personally would imagine that the name is of his own creation.
It's not a particularly creative name and therefore it's quite likely you both could have come up with the same name.
And, since his name has no space, I would guess that he tried "The Blocklander" but it was taken by yourself.
It's a bit like on big MMOs and Game networks like Xbox Live you'll find lots of players with the same name, but a different number at the end, since they've all come up with the same name.
Difference here though is that we don't have quite as many players so two people with the same name are much more likely to see each other.
Pop onto his server next time and ask him if he came up with the name himself or saw yours first.
