'Psiioniic falls back down' was certainly on the list of possibilities Childermass had in mind with this dare, though that fall did sound particularly bad. It could be he's just acting out drunkenly, but it's enough to get Childermass to set his notes aside and stand up from the trailer steps.

A few steps later, he's dropped down into a crouch next to Psi. He'll check on him, but he's not going to reach out to the troll unless it's clear he actually does need the help.

"Alright there?"

Which roughly translates to 'you dead yet, man'?