Though Hades had tried to reassure Hythlodaeus (not terribly successfully) that he's fine, all pretense of that fades away the moment his friend violently throws his phone at the wall. That's certainly on the "Uh-oh" end of the spectrum of Hades's breakdowns, and Hythlodaeus hurries over almost immediately; their bond makes obvious his worry and concern - though there is also a smidgen of reproach at the fact that Hades tried to lie to him.

"Hades, what happened?"