I don't think his name is real.

I live in Vietnam and when I showed this to my wife, who in turned showed it to her cousins, everyone was fairly incredulous claiming that there is no way this was a real Vietnamese name.

Bich is not a last name used here, it's actually a female first name. Dat is also not really used as a middle name either.

Bạch is a last name, so the only thing I can think is that there was a mixup in immigration, similar to how european last names changed during migration to the US.