New DH article (major spoiler if you haven't read the book!)

[Ruth Roulston]

Ruth:
My impression was that Harry responded as a student should to a figure of authority.  Professor Snape motioned Harry to be quiet and Harry obeyed the command.  The situation did not alter Harry's opinion or feelings about Snape.  Both Dumbledore and Snape issued instructions for Harry to be quiet and the boy followed those instructions.