7-1-4-a-2 requires all offensive players to be lineman or backs. The second player in position to receive a hand to hand snap meets the definition of back. My opinion would be that this is not an illegal formation. What is the foul?
The second player in position to receive a hand to hand snap meets the definition of back.
Actually I don't believe he meets either definition based on why the "d.2 paragraph" is there in rule 2.27.4. It's there because he's a linemen (breaking the waist of the snapper when in position to receive a hand to hand snap), and a back (he's directly behind the line). If he clearly met the definition of back then there's no need for 2.27.4.d.2 (the "QB exception"). Also note that the phrase states "the player" (not any players or the players) - it's singular. The rules change documents and discussions that we had in 2011 made it pretty clear that this exception was for 1 player only.
I also believe that when this was changed in 2011 the idea of any player being in "no-man's land" no longer exists. IMHO with the three definitions in 2.27.4.d (from 2011) it covers all possibilities. He's either a lineman (the snapper and all players breaking the waistline of the snapper), or a back (all players that are behind the NZ and NOT breaking the waistline of the snapper, and the QB (the player in position to receive a hand-to-hand snap) - I don't see the "in-between" any more.
IMHO the foul would be a 7-1-4-a-2 violation (Illegal Formation) in that the "2nd QB" is partly both a lineman and a back since he can't get QB exception.