If the cuffs had given Sirius some difficulty, James would have moved to help him. As it was, it was best if they weren't both distracted by their friend, just in case someone came charging down the stairs after them. And there was also the matter of Remus's things - he'd had a wand on him when he'd been taken, and... he glanced back at the chained werewolf. He'd also been wearing pants.
"Accio Remus's wand," he said, not sure if the spell would work. Might as well give it a try though, right? Wand was by far the more important of the two items Remus was missing. And it worked - he caught the wand easily as it came zooming towards him, so he tried the other spell. "Accio Moony's pants."
That almost made him laugh, belatedly, but it worked. At least, he had a pair of pants for his friend now, and a wand; he was fairly sure they had belonged to Remus, but in the dim light he wasn't entirely sure. His eyes had adjusted enough that he didn't want to light his wand and draw attention to them, so it would have to be good enough.
Moving away from the door, he went to help Sirius get Remus to his feet, but paused before handing over his friend's wand. "Wait," he said, as a horrible thought struck him. "Moony, what'd you get me for Christmas last year?"
God, it would be awful if they thought they had rescued Remus and it was actually an impostor, someone impersonating him. Polyjuice was entirely possible, since they'd captured him, had access to his hair.