Since we'd all be talking at the table, Imma use this thread as us talking at the table.
I'm going to go a little meta and assume the wizard guy is either a simulacrum or he has a Ring of Mind Shielding. It's just as common as my helm, and is basically a block to anyone trying to divine information about him, unless he wants them to. I had one once for one of my characters. It's pretty awesome, and grants some protection from this kind of abuse.
So basically, we can't trust the wizard is on the level. He could just be a smart wizard who doesn't like his mind read. Makes sense to me. But he could also be sending us to our death.