Do mods actually have the power to deprive the user of the usual notification by PM?
This was brought up some time ago IIRC, and I think there's an option not to notify the user.
On previous occasions, I did notice that my post count decreased by 1 or 2 but received no notifications when they happened.
Interesting. I can think of no scenario though where not informing the member their post had been deleted, would be sensible, or fair.
If an entire thread was nuked, that could account for the missing posts. OTOH it could be that option the mods have which you mention.
As someone has said keeping your own records could be useful. Is there some plugin that can auto archive every post you make?