"Super soldier," he corrects, keeping his eyes on the doctor's face. "I don't care about power, sir. Just about defending the helpless."

Maybe something about the way Steve answers will strike Bones as familiar, or maybe it'll show in his readings. Or, just maybe, he'll take a closer look at the kid stretching out on the biobed and realize he bears a striking resemblance to someone else on this ship. If the scanner doesn't read his blood as being red, white, and blue, then the thing's broken.