To be fair, the only place the words ‘open’ and ‘source‘ appear in the readme are once in a sub-heading, where it’s phrased ‘open-source’. It’s clearly labelled ELv2.

Possibly more of a subtle miscommunication or misunderstanding than a deliberate lie.

Don't kid yourself. The title of this submission itself starts with "Open Source". Moreover, the author has made the explicit decision to not fix the readme.