Gosh, Tina, I'm sure that was disturbing on many different levels.
I really hope this has terminated the situation. We do tend to believe that everyone has the same agenda as the rest of us, and it's a real shock to realise that that might not be true.
Forgive me if I use this opportunity to point out to other members that just because someone is a regular poster on a forum, it does not mean that they are "safe". I'm sure that 99% of the posters here are just what and who they claim to be. I would be cautious, however, about any poster who reticent about their personal situation.
There are various questions that anyone should consider:
1) Do you know the sex of the poster? While it is not absolutely necessary to specify if you are male or female, there is no reason why someone should be reticent about this fact. If you have no idea whether a poster is male or female, think about whatever they may be trying to hide.
2) What is their connection with dementia? Anyone can "claim" to have the same experiences as you, and that tends to result in a level of trust, but if they never mention whether it is their parent, their spouse, their brother or sister, then again, you should consider if that poster is hiding something.
This is a very boring post, I know, but the only people who have been in any way "vetted" on this forum are present and past forum moderators.