It's probably the same person, but without solid evidence, no one will ban him regardless of what he posted on the forum, or his opinion on what Bitcoin really is. As I see the user in question can not be accused of ban evasion through connections with an address, but he/she maybe is not using TOR/VPN, so admin can check is there any match in IP address.

In the meantime, it's best to use the Ignore option, any further interaction really doesn't make sense.