There is no evidence provided of them being alt accounts.
He admitted it himself:
Yes, the account is in control of me.
The Flag is on poochpocket, not on hacker1001101001. I didn't read all the details, but it doesn't seem right hacker1001101001 can confirm this on behalf of poochpocket. Anyone can claim the exact same thing about my account, that doesn't mean it's true. So it shouldn't count as evidence.