Hi Ken ,
Most GT will strike the lure from the side , I once watch a GT homing on my friend's stickbait from a tower of a sportfisherboat , the GT came from behind and stop momentarily , overtook the lure to flank it and turn to hit the lure from the side , most of the teeth marks suggest the same . Only wahoo seems to take the lure from behind and even narrow barred mackerel will hit the lure from the side at a slight angle .
As for the tail hook facing down , with swivel it tends to turn on every jerk of the rod tip , at least when I use SJ hook .
Jon .