Yes I agree the manager wasn't practicing good staff relations by talking to you like that, even if you had been putting the boxes in whole there would have been much more amenable ways to approach you.

My response would have been to say as Tish suggested, politely let him know you had been breaking them down. Overall in work places I think politeness goes a long way, I think your own politeness may also possibly remind someone like him that they forgot theirs.