I'll just jump right into an example to illustrate my question:
A Human Blitzer uses his tackle skill and rolls a [target down] and a [tackler down]. Because of the headline, both apply. Does the Blitzer's ability still take effect (giving his manager a pass action)? I don't see any logical reason why one "tackle" should take effect before the other, which would make them simultaneous, which would mean the Blitzer is in the process of losing all skills and abilities (for being down) at the same time the ability is activated, which means I'm stumped.
(Simultaneous application seems to be implied with a double-tackle roll bypassing "when downed" abilities, as well, I'd say.)
No, he would not get passing. When a player goes down, they lose everything else on the card. Because both these dice are rolled and kept due to the headline, the effects are simultaneous. So both players go down.
Only if the players had something like Sure Hands or Dump Off would they still get to use that ability.