I think calling someone a "bad person" (which is itself a horribly vague term) for one situation where you don't have all the context is something most people should be loath to do. People are complicated and in general normal people do a lot of bad things for petty reasons.

Other than just the label being difficult to apply, these factors also make the argument over who is a "bad person" not really productive and I will put those sorts of caveats into my writings because I just don't want to waste my time arguing the point. Like what does "bad person" even mean and is it even consistent across people? I think it makes a lot more sense to label them clearer labels which we have a lot more evidence for, like "untrustworthy scientist" (which you might think is a bad person inherently or not).