I think you're right, Bocci.
Here's an article I found about it. Ironically enough, the Seahawks benefited from this back in 2006 and Scott Linehan wasn't too happy about it.
http://sports.espn.go.com/nfl/news/story?id=2628616
The yellow flag flew, and many of the Rams began to celebrate in anticipation of an offensive penalty that would require a 10-second runoff, which would have meant the game was over and the Rams won.
Wrong.
The Seahawks were whistled for an illegal formation, not a false start. The false start penalty would have required the runoff. The illegal formation call simply moved the ball back five yards.
And this was back in 2006. Still can't believe they haven't changed the actual rule in the rule book. I know Pete wasn't happy about it. You could hear him screaming "runoff runoff runoff!" just from watching on TV. I'm sure he'll have something to say about the matter behind closed doors.