The hug certainly doesn't help with surveying his injuries, no, but the tightness of the hug does something to reassure Magnus. Jamie's here and he's whole and he's safe, because Magnus is now here to protect him. He's not going to let anyone get near him again, especially not Peter Pan.

"Good, good." At least he wasn't alone then, dealing with all that. Magnus gives him another squeeze before letting go. He only takes a half step back and away. "You're all safe now."

Unless...

"Did he follow?" Magnus cranes his neck to look behind Jamie at the path they all had taken. Most of the kids are familiar to him, at least in passing, but not all.