Everyone has "bias". That's normal.
However, if you highly suspect a question is a Push Question; not a good-faith attempt to gain historical information, but rather a (subtle?) attempt to push a particular agenda (or even just troll) in the guise of a question, that's a different matter entirely.
This goes double for any question having to do with Nazis or the Holocaust. We have already established site policy that anything to do with Nazis and/or the Holocaust has a higher bar for being an acceptable question. We get too many crypto-Nazi fake questions on those subjects to be lenient with them.
In that case, feel free to use all the tools at your disposal. Downvote the question. Vote to close it. Flag it for moderator attention. If you think the user in question has been making a habit of this kind of content, add a custom mod message explaining your problem with the content being produced in detail, along with links to further examples if you have them.
This is you all's* site, so you get to decide what the standards are. If you personally are just way out on a limb about the poster's intentions, your solitary close and downvotes will get outvoted, so no harm.
But if you aren't alone in your suspicions, we mods will have all the backup we need to take action.
* - I know the second-person plural isn't precisely standard English, but the distinction is important here, and I think my native American Southern Midlands form is less jarring than "y'all's".