Unfortunately I seem to have conflated facts. 4chan pol has flags, and spez had a bit of a tiff with The Donald users where he changed their posts without consent (removing his name I think) that led to some consternation.
There were also investigations showing Russian activity in The Donald. But somehow the flag story is something I seem to have dreamed into this story. Doesn’t seem have happened (even though I have oddly specific memories about it).
That said I have no idea if what GP said is true or not