There's no evidence people were summarily executed for bad answers. People were detained through this method though

Operation Greif

What was described above is someone asking another person a factoid about baseball and then shooting them if given an incorrect answer.

You're referring to instances of captured spies (potentially captured by said baseball questions) being tried as spies and executed.

The former did not happen, the latter did happen (which I don't think anyone here would've disputed).