His claim is totally wrong. Allah The Glorious never does injustice on any one and He never force any one to do something then punish him for doing that. This is one of main facts in this existence. Allah does not need any thing, and every injustice is initiated by need existing or thought by the wrong doer. This never exists with Allah (SWT).
Allah created all humans with inner guide to the truth which is the intellect and outer guide who are the prophets and Infallible Imams.
No one is forced to be non Muslim nor a Muslim. Every one has his own decision through his own intellect.