sometimes, the govt will "piggyback" on a real attack. Or they'll exaggerate the recount of what happened. Or they'll know about it and let it happen, or even wagered on stock market about it lol. Or they'll be working with the bad guy, trying to build evidence, and he'll do the attack - in which case they may pretend they never met him.
In those cases, the attack is very REAL. However, it certainly doesn't happen like the "official story".