If Julien can hear the ground moving pre-emergence he might alert the network and call in a bomb threat to try and clear out the area, but it looks like there won't be enough time for that to make much difference. In the aftermath that would mean a record of his having called a minute before anything happens.

He'd want to help with first response stuff, I think, and that would set off the harpyzation. (and shit going down would delay his breakdown by quite a while) It's possible he could also echo back some of Yuuya's heavy weaponry? Either way I think he'd be pretty visibly a bird creature. So I think he'd have to leave home and go into hiding somewhere - the clinic might also be checked out as a place he's pretty openly involved with.

Julien might be able to leave the city eventually - with help - but for a while I think he's still in Locke.

ETA: And he'll want to leave the city soon after changing, discover that the boundary's gone and he can't change back, and come back and quietly break down. If someone would drive him in the messy aftermath, that'd be great!

Later he might be one of the more open reincarnates. Possibly a little famous. Idk yet!