Who in the chain of command of the Capital Police made the decision "that the song could be interpreted as a “protest” and may offend someone?"
Do they know what our National Anthem is about?
Their action supports the "America Last" position of the Democrat Party.
It probably came from the top. I noticed that the choir was told to stop singing immediately after it sang “No refuge could save the hireling and slave from the terror of flight or the gloom of the grave.” Because these words offend woke sensibilities, it would not surprise me if the Capitol police were given orders to stop anyone who sang these words.