a week later we both get 10 coins, he sends the coins to my address , and then start a scam accusation topic, saying I used an alt and broke rules, i get tagged for something i never did.
As far as I know, this is not enough evidence.
Let's say:
Account A post: A address.
Account B post: B address.
Account A sends 10$ to address B. "It is not proof"
Account A & B send 10$ to address C. "A&B same wallet"
Also, writing style, activity times, and synonyms are considered evidence to strengthen the doubt.