The company has either paid for an interview process study (hence the psychologist), or have paid for a solution. While these might be useful to filter out large candidate pools, the extent you describe seems overkill.

As others have said, if the company is this deep in the analysis, either they really know what they're doing, or they have no clue. If they really know, they will be able to cite statistics on false positives and false negatives, describe the mitigation process (correcting for the falses, as well as avoiding discrimination and other biases). They should be able to estimate savings over a more conventional system. And they should randomly take a few fails through to the next step (blindly), to evaluate the metric, or it will be "correct by definition".

If they don't know what they're doing in the interview process, chances are good they don't know about much else either (though it could be just an HR wonk driving it). Update: Fixed typo.