BlackBlue - the reason you get a bunch of outer hookings with trailer hooks is because the fish hit the fly from the side usually so the hook is hanging on the outside of their face, this is also part of the reason you dont get solid hookups sometimes because they dont actually have your hook they are holding the fly
I think this rings true alot with Bull trout because they are very aggressive and voracious predators that will eat anything in their paths
steelhead of course like to follow the dang fly into shore alot of times deciding whether to strike or not until you take that first strip then WHAM !! they go for it, this is why they get the hook most of the time because they are coming up behind the fly.
just my theory
Awesome fish Dereke