No. It's an awfully convenient substitute for an argument, but ultimately just an abused heuristic. There's nothing precluding a "bad" person from conducting good research or giving good advice.
If you don't have time to verify/consider something then sure, probably don't get your advice from hitler. But in an argument its a cheap and disingenuous dismissal which doesn't actually bring you any closer to truth/resolution.
In this case it's a compendium of interviews from current personnel. Maybe the implication is that the data is fabricated but the only evidence provided is in the form of "the author has opinions I don't like".
If you don't have time to verify/consider something then sure, probably don't get your advice from hitler. But in an argument its a cheap and disingenuous dismissal which doesn't actually bring you any closer to truth/resolution.
In this case it's a compendium of interviews from current personnel. Maybe the implication is that the data is fabricated but the only evidence provided is in the form of "the author has opinions I don't like".