I agree. Cannot find anything on the poster either - assuming that is his actual name, doesn't seem to have any social media presence elsewhere which is odd. Also the written English is not very 'second language' for someone supposedly Norweigen. It has too many grammatical shortcuts to be anyone other than English IMO.
I've looked too and yes, the poster seems to have no online presence at all bar that Twitter account and, as you say, the English is very 'English' for a supposedly foreign account.
It's a convincing effort that definitely took me in initially, but the complete absence of other sources is giving me major doubts.