kathy, for some reason I could't get the video to load but to respond to your question, just pulling boards off is indeed enough to get a hive riled up. A lot of time you will have comb that is attached to the boards, and when you pull them off, you are breaking comb, which the bees do not like. Plus in my experience, older hives, say 3 yrs or older can be a bit testy. Seems the longer they've been there the more defensive they can be.
Sincerely, JP