Clint's definitely feeling ripples of anger at being confronted with something that he associates with loss and regret and a handful of other emotions, but it hasn't made him incensed enough to vent his rage out loud. So when Bucky's shout comes, along with the sound of shattering glass, Clint is quick to stop what he's doing and dash over to the other man's side of the maze.

"Hey, man, what happened?" His first instinct is to try and reach out and establish some form of physical contact, but he hesitates, because all things considered, he doesn't know Bucky that well, and he doesn't want to cross any boundaries that might agitate him further. "Look, why don't you move over here away from that thing, and take a breather?" He tries to keep his voice low and as calm as he can make it, because whatever he saw, it's clearly riled him up.