for the sake of argument, i want to believe that they are the same alex on both twitter and bitcointalk, but that proves nothing, unless he can prove that alex owns that telegram account too.

you see the twitter addition to his claim is nothing but a deceiving tool, it's like when you have to solve a math equation, and you start by proving that water is wet, while water is indeed wet, the math equation can still be wrong.

OP needs to prove that alex is the one who contacted him on telegram.