Oh man, I hear you! Only recently started to play LA and even more recently started to 'get it'. Was running over a crest when 2 HAs and a Medic came the other way. I turned and high-tailed it to a tree to lose them but they followed. So up the tree I went and they just ran around and around the tree trying to find me while I picked them off one by one. NO ONE ever looked up! lol I sat in that tree until I was out of ammo and picked off a bunch more peeps. LA is a gem in the right situations ... trees ... who knew?!
It has to do with sprint I'm pretty sure. Toggle sprint off as you go through the window and you'll fit through like a greased up hotdog. With sprint toggled on you'll bash against it like a fly on a screen door.
It's mindblowing to me how well it works when it does. Now that the game's been out for a while, it works less well than it used to. The first couple weeks after it went live, you could run out of ammo sitting in a tree/obscure tower spot. These days, not so much.
Not the LA, its their special perk. inf have cloaking/snipers, HA have shields/LMGs, LA have Jet-packs/luscious \-******-hair