As far as fake hail mary trick plays are concerned, I'm not sure if it ever occurred to the coaches to whip one up just in case.
3 WR to the left, Tate to the right, Leon in the backfield to "block".
Russell takes the snap, runs around for about 3 to 4 seconds, finds a seam on the left side and starts the scramble. Leon hangs around in the backfield, maybe chips a rusher on his way upfield, but he kind of lingers with Russell across the field laterally. Once Russell getting hit is imminent, he pulls the trigger and hits Leon on a long lateral pass and from there, its just like a punt return and he probably has to make a guy miss and then get a good block from Tate to get in.
From the 50 yard line this is totally imaginable.