Trivia point for the day: during the certification test for the 747, one of the flight attendants did exactly that. The standard is that the plane has to be completely evacuated in 90 seconds with only half the exits working, and during the test the slide failed on one of the "working" doors (1L, if I remember correctly). The FA just moved forward over the seats -- in those days, at least, they did fold forward -- to assist with rerouting the "passengers" to other exits. Quite interesting to see, if you ever have the opportunity (it was filmed).