Physics rule

But also Jimmy (or whoever saved him) now has two broken arms thanks to a human sized object falling onto them at terminal velocity.

... Two broken arms...? Oh no... I remembered that Reddit post.

His brain definitely would NOT experience the same g-forces as hitting concrete. You have less than an inch of deceleration space against a surface that hard, whereas getting caught by superman would probably give you at least twice as much space, if not way more, which would reduce your g-forces by more than half