How does a spammer start a thread under a registered user’s account name?
When the actual first post by the spammer was removed, the next post that was non-spam was listed as the originator of the thread.
The first post in the thread was removed. Raveman did not post the OP.
He didn’t, the OP was removed. Look at Ravenman’s post,it’s a response to the vanished OP.
Aha. I forgot about that.
Johnny L.A., if you’re trying to disavow that sheep ranch thread you drunk posted, it won’t work.
SHEEP RANCH??? Where? I’m there, dude! 
I’m the miscreant. I was on my first cup of coffee this morning and discovered 10 “report this posts” to my emails during the night. I quickly discovered that one spammer was responsible for all. We have this handy dandy ability to see all of it’s posts, click on some boxes, and away they go!!
But, in my early morning stupor, I forgot that there were responses left when I disappeared his posts.
I caught some of the remaindered threads over the next hour, between shower, coffee, and disappeared them, but must have missed at least one.