Yes it is indeed an Asian Arowana, though I'm not sure if it's a Red (hybrid?) or I think more likely an RTG (Red-tail Gold).
G
Galantspeedz
would know better.
And to answer your other question yes it most assuredly is very illegal to keep such a fish in the US (without proper permits, which are generally are only issued to research institutions or zoos) -- they could be fined a lot of money and face jail time too.
As to why they haven't been busted yet I guess just blind luck and authorities didn't know (but that could change soon as certain gov't offices are known to peruse MFK).
Of course many will (justifiably imo) argue that the US laws are very outdated (taking into account the tremendous success of commercial Arowana farming), but that's neither here nor there when it comes to current status of related laws and enforcement thereof, pretty risky to say the least, let alone in a public setting.