If they wanted to see how many would believe them i think they got a good.....zero people there lol
The sheer base behind this is
A). The game haven't been out long enough for ANYONE to EV, IV ALL 493 pokemon
B). As stated before to have seen ALL the pokemon you would of had to have used cheats or hacks because of certain pokemon, Arceus being one of them and i don't think the Jirachi/Deoxys events were done outside of Japan (correct me if im wrong/if i am sorry)
C). You say he has never traded to anyone so once again how did he get every single pokemon? Did he go out and BUY EVERY GAME? Again explain Arceus/Deoxys/Jirachi/Etc?
D). In your first post you say and i quote: "you can't train anymore pokemon and you have gotten every item and all the money you can earn... Can Anybody Beat Him?"
How can he have EVERY item? Does that include the event items like the Darkrai and Shaymin event items because if it doesn't then im sad to say they dont have them all do they...
E). Just because this person has took every pokemon to level 100, got maximum ammount of money and "Has All The Items" (See example D) this doesn't make your friend unbeatable. For Example if i was to use a EV, IV trained Ancient Fossil Team with movesets sorted by, lets say for arguments sake, a member of Game Freak i would pretty much give any randomly made level 100 team a massive run for its money.
Now to say i haven't just ranted at what was said would be a lie BUT as you can see there are some massive sections of your claims that has faults (Such as having every item but not using hacks or cheats. Same for all pokemon without trading or GTS {{You state he has never traded with anyone}}....)
Anything i've missed out please feel free to mention