I think the way these people reacted confirms that it would be a very bad idea to have them at any conference. I wish they were named so I could avoid them now.
There are several reasons to believe a blog post over a told-in-person anecdote; for one, this is more or less an open forum with no time limits or constraints on research. This is when combined with the fact that these possibly-incriminating* details of the story were provided voluntarily, which generally adds credence to a claim. Until an opposing blog post appears telling the opposite story (which makes perennial discussion similarly easy to take place), it makes the most sense to believe this account over a secondhand story of a story that doesn't even have a written record.
* If the story of the stalking, etc. were true, it would be damaging to the author's reputation. It would naturally be in the author's better interest to cover it up by not mentioning that detail given that it was true.
I'm sympathetic to the author but now I'm finding the epistemology here interesting to talk about.
Firstly I generally think of information provided voluntarily as being more suspect than that which is elicited, coerced or happenstance. Think of the criminal who under questioning volunteers to "help" the cops by putting them on someone else's trail with a false accusation. (Made to seem offhand, of course.)
This applies to the stalking example too - in terms of possibly being able to frame and spin something by mentioning it first, when you know some version of it is going to come out regardless.
I agree with your point about written records, at least to the extent that writing behooves the writer to consider things carefully. Although it still doesn't preclude someone's being inept or unwise about it.
Just speaking generally, not necessarily about this case.
While in that particular case, volunteered information seems suspect, I would argue that is only so because the person providing it is already under questioning for something. The would be the exception rather than the rule, since in the vast majority of cases, no attention is the desired scenario for a person who has done someone else wrong. And generally speaking, the easiest way to achieve zero attention is by not informing others as to the existence of a situation.
I don't absolutely believe OP's story, but an important feature of OP's story is not naming any names.
The story contains various propositions that can basically be divided into:
1. propositions that can likely be independently corroborated by large numbers of people:
--- the conference really happened (we are not told which conference where, but if we knew that, numerous people could be found to attest to it, if it had been real).
--- that the organizer was loudly accosted by the woman, accusing him of stalking: this is a public incident that supposedly happened, in front of witnesses.
--- the non grata couple is real; people don't like them for some reason and warn conference organizers
--- the non grata couple are known for harassing behavior
2. claims made by the organizer, like:
--- he denied participation in the conference to the couple
--- he was harassed by the woman with repeated contact attempts
--- the woman's allegations were false
The claims under (1) are verifiable true or false. If they are true, they lend overwhelming credibility to (2). Basically if everything under (1) is true, it's almost inconceivable that the (2) claims aren't.
