There's certainly evidence pointing that way: "the sibilant whisper" - "dry as dust" - "the high-pitched chuckle" , "What's your name?" "That is the riddle, young Ravenclaw" , and indeed "for now you have seen how the others stayed silent"...

But while I could easily believe that Jeremy Jaffe is better at projecting false emotion than Hermione is at discerning it, I have a much harder time believing that He-Who-Must-Not-Be-Named, whose eyes blazed crimson like miniature suns, could forget the value of surface appearances.