Question for knowledgeable people about the Eagles/Giants game

[Chingylol]

During the 50 yrd catch by Desean Jackson, the Giants were called for illegal hands to the face, which was declined. After the play, Desean was called for taunting.. They ruled the penalties offset and therefore, they replay the down.. is this correct? Even though the taunting penalty happened after the play, wouldn't that just make it a 15 yard penalty from the spot of the ball?

[RollTide]

That had me confused as hell. But apparently it was the correct call. Per PFT:

The prevailing thought was that Eagles should have been able to decline the penalty against the Giants, and then to have the 15 yards walked off after the play, giving Philly a 35-yard gain.

But the outcome reflected the proper application of a strange donut hole in the rule book.

The process gets started at Rule 14, Section 1, Article 9: “If there has been a foul by either team during a down and there is a dead ball foul by the other team in the action immediately after the end of the down, it is a double foul, and all rules for enforcement of double fouls apply (see 14-3-1).”

Regarding double fouls, Article 14, Section 3, Rule 1 provides as follows: “If there is a double foul . . . without a change of possession, the penalties are offset and the down is replayed at the previous spot.”

In this case, a key exception almost applied, but ultimately didn’t. “If one of the fouls is of a nature that incurs a 15-yard penalty and the other foul of a double foul normally would result in a loss of 5 yards only (15 yards versus 5 yards),” the rule book states, “the major penalty yardage is to be assessed from the previous spot.” Since the penalty on the Giants entailed a five-yard penalty AND an automatic first down, the exception didn’t apply in Jackson’s case. Even if it had (for example, if the Giants had simply been offside), the Eagles would have had the 15 yards walked off (or, in this case, half the distance to the goal) from the previous spot.