Is it really "guessing" a seed phrase if there's nothing in it? Lmao. What he's describing is him pretty much just like generating a wallet. The difficulty is actually in guessing a wallet address that someone actually owns and use.
The guy is just lying, or lucky, Brute force doesn't really work with seed phrases. And I don't understand why he is trying to do it by himself; if he's interested in it he can use some program to try those combinations.
It technically can work, but in practicality no. Very
very unlikely that some bruteforcer lands upon a wallet with funds in it.