Thanks for all the information guys ^

He will not try this then, but rather get a correct visa into his EU passport.

Which leaves me (or better him ) with the question if the consulate handing out the Visas will actually double-check with Chinese central register (is there any?) if he's Chinese national?

He told me he won't have problems in getting a new Chinese passport in China itself. (Asked him about this, as mntblue suggested to take care about it.) Probably he knows someone there