Tim's expression said that he wasn't sure he'd take drowning over getting smashed by a flying tree branch, but at this point he wasn't going to argue. He nodded and pushed up to his feet, doing his utmost not to burden Raylan. He noted the fist in his shirt -his turn to be on a makeshift leash- and he reached for the older marshal when the man slipped. Raylan caught himself so Tim gave him room to move under his own power, though his hands remained in the 'cover the civilian' spread to either side of Raylan's shoulders; ready to take him down to safety.

He didn't know where the entrance to the tunnel was located in this building so all he could do was follow Raylan, stay close and try to protect his back. If the older man was right about the tunnel and they didn't end up drowned, they could pick up the argument where it had been left off.