Here's how it all went down....
On the snap, McCluster ran left as if it were an end-around and took the handoff.
At this point, the 49ers defense -- specifically safety Dashon Goldson -- stopped and started to creep to the line of scrimmage.
At that point, he was already toast. McCluster continued running left but pitched it back to Cassel as if it were a double-reverse.
Cassel took the ball and with Goldson now more than five yards behind, hit Dwayne Bowe at the edge of the end zone for six.
After the game, Cassel told reporters that being aggressive like that gives the team confidence. "In the huddle," Cassel said, "you can see it in the linemen's eyes. They get energized and excited being aggressive."
And, yeah, double-reverse flea-flickers (or whatever that was) that go for 45-yard touchdowns also get the fan base pretty jacked up.