He was friendlier in the open? I'll have to think about that.
And aggression? Several quick thoughts: one: emus 'beak' things as a way of exploring them ('cause they got no hands to hold stuff with . . . ). Uno Chick once grabbed my nose, and I nearly died of fright. So if an emu is 'pecking' at you, don't be too alarmed. (Note: they will peck at shiny things. They luuuuuurv shiny things!!)
Two: notwithstanding 'Youtube Emu Kills My Wife and Family and Sets Fire to Our SUV,' we have literally almost no reports ever of emus attacking people -- at least without provocation, in the open. You never met Eric the Emu, the 'double alpha' bird who reigned here. I'd rather have gone into the ring against an hydraulic ice pick than against Eric, but that pertains to cornered critters defending themselves. (Emus
hate to be cornered or constrained in any way. Getting them on to trailers is apparently an art.)
[Note, readers: cassowaries and ostriches are notoriously aggressive.]
All this is to say that if Ernie the Emu was gonna attack you, it'd already be all over. The speed with which they strike is awe inspiring. He'd have just run up to you, and slashed a chunk of feathers out of your feather pyjamas.
Do I understand that your reluctant to hand feed him? Several things go very well together: silence and stillness and food they like. Sit yourself down on a chair. Throw food down all around you. Sit really really still. And quiet. Still and quiet. Ernie will likely approach you. Eye you and the food. Drop to his knees, and sidle forward to eat. If he comes close enough, you can give him a little stroke.
If you try to hand feed him, don't mistake normal emu lunge-peck-twist-snatch for aggression. I hand feed all the tame-wild birds here. Some are accurate and gentle. Some will almost drill a hole in your hand.
(This is a great way to get to pat wild chicks -- food makes them forget to pay attention. If you ever really really need to examine a chick, you can snatch it up using this technique: get the entire clutch quietly eating around your legs, and then snatch up the chick in question.)
[Wait. I can hear them out the back. Here is Uno Chick, the adult; and a yearling, one of Eric's orphans:
https://imgur.com/a/sM7p5 ]
Supreme Emu