On a practical level: every time I've included a controversial attention-grabbing aside in a post, I've regretted it. The discussion and I assume people's attention always focuses on that aside, at the cost of my primary point. If you're trying to stir up anti-this-person sentiment in general that might be a plus, but if you want your actual argument to be considered on its merits it's a severe impairment. If you think the accusation is important I'd strongly encourage you to split the posts.

The main thing I track is whether I expect healthy information flows when the information is relevant. 

If someone was arrested for robbery and I'm citing their work on Quantum Mechanics, I wouldn't think it relevant to bring up. If they were being considered for a job looking after finances I'd want to make sure the person hiring them knew. 

If I felt like nobody would tell them because it was all hush-hush, then I would be more likely to write something about it publicly... though not really in the stuff about quantum mechanics? Seems unfair to punish them in every possible channel, as long as they're receiving the actual costs involved (job opportunities, reputation amongst colleagues and coworkers, etc). 

If I thought it was being super quashed, I might have a footnote at the start of my discussion of quantum mechanics saying "For the record I have ethical concerns about this person's behavior in other situations, here is a link to a brief shortform comment by me on that" or a link to info about it, but otherwise not bring it up.

In general, I think most disclaimers aren't worth it.

The penultimate word of your question answers it.

If someone else, unprompted, then cries stinking fish, you can suggest that that discussion take place elsewhere.

This seems like a strange thing to ask.

If someone has done something illegal, alert the appropriate authorities. If the person has violated the rules of some institution or group, alert the appropriate leaders or administrators of that group.

Bringing up any of those things in the context of mentioning a person in an unrelated context seems bizarre and pointless. The motivations that you list in your explanator comment… seem like non sequiturs, quite frankly. I don’t understand how any of those things translate into bringing up this matter when writing about unrelated things.

Again: institutions (including but not limited to the government) that have laws or rules also have mechanisms for the enforcement of those laws/rules. Avail yourself of those mechanisms. Don’t involve unrelated things, people, discussions, contexts, etc. in the matter.

I really hate attempts to discuss topics where details can't be shared.  I suspect the right answer is to resolve, or at least acknowledge the accusations clearly, separately and in advance of citing the person.  Then you can have a footnote pointing to that information, and stating that you find it irrelevant to the idea you're discussing.

Note that by doing so, you are to some extent supporting the apparent LW reaction to ignore the behavior - you believe it happened and was significant, but you don't want to participate in any consequences, and still want to give credit to the person for the idea (and/or use some of their fame to highlight the idea).  

Alternately, if the idea is standalone and has sufficient support without the source, then say "this post is intended to stand alone - it's been discussed before, but not in this context."  If someone else brings up the previous author and their crimes, then you respond with it's irrelevance (in your mind), but don't do it proactively.

All of this is dependent on the specifics of what the person did (or is suspected to have done), how tied to the person the ideas are, and whether it's important enough to tie yourself into the drama.

Some considerations I have:

(Spoilered to make it easier for people to write their own unprimed.)

If a bad experience goes unheard or unobserved somewhere the possibility of it being allievated is quite hard.

I would like to know if/that I would have hurt somebody even if I would initially disagree how that is forceful (but no conditionality that it needs to end or go in the direction of me agreeing).

You present the question as a *dilemma* with only two choices:

a) Give credit to person P's idea I. Discredit the person P by repeating accusations A and judging them believable. Risk criticism for stirring up irrelevant drama.

b) Give credit to I. Be complicit with P by staying silent on A.

But is this really a dilemma? Maybe you're mixing up two topics. Why not write *two* posts, one for each topic?

In the first post you discuss the accusations A. Explain why you feel the need to give those accusations credibility by repeating them publicly and judging them as believable. Let the discussion take its course. Wait for the result. If you really believe that these accusations should be aired here, then do it properly. Give the accused a proper chance to defend themselves. Make sure that you understand your own motives. 

In the second post you then discuss the idea I. Any discussion about A would be off-topic for this post about I.