I don't believe this is possible and actively protected against in the dht protocol implementation.

The return value for a query for peers includes an opaque value known as the "token." For a node to announce that its controlling peer is downloading a torrent, it must present the token received from the same queried node in a recent query for peers. When a node attempts to "announce" a torrent, the queried node checks the token against the querying node's IP address. This is to prevent malicious hosts from signing up other hosts for torrents. Since the token is merely returned by the querying node to the same node it received the token from, the implementation is not defined. Tokens must be accepted for a reasonable amount of time after they have been distributed. The BitTorrent implementation uses the SHA1 hash of the IP address concatenated onto a secret that changes every five minutes and tokens up to ten minutes old are accepted.

I believe you would have to know the torrent first, then you could discover other nodes. This is probably why that tool can't tell you anything outside of it's known list of torrents.

Source: http://bittorrent.org/beps/bep_0005.html

I have a peer with static IP address, is there any tools to extract what he/she was downloading?

Not directly, that's not how the bittorrent protocol works.

That website you reference doesn't work the way you are thinking it would work, it does not examine an IP address & then somehow figure out what it is downloading (this is impossible). That website does exactly what every other copyright troll service would do, they monitor specified torrents, load them in their own torrent software, save all the current peer IP addresses associated with that torrent, then they claim you were downloading that.

So with just an IP address no you could not do anything like that. You'd need to scour the internet for as many torrents as possible, load all the current peer IPs into a massive database, then you can search the IP address in your database & see what comes up. In other words you need to know the torrent(s) before you know the peer IP addresses.

How is this website so wrong?

I don't have a static IP. I'm not in the United States. I'm not even in North America...

I'm literally on another continent which can be very easily verified using nothing more than a geoIP lookup, but they somehow place me somewhere 3,000+ miles away. And no, I'm not using a VPN.

The website you mentioned made me laugh cause it mentions some weird files I never come across.