Palin had just visited a museum or historical exhibit where Revere's ride was being discussed. It does make sense that P.R. was indeed warning the Brits as well as the patriots, because the unavoidable signs of alarum (church bells ringing in the night, etc) would let the redcoats know they no longer had the element of surprise.

This was unavoidable, it was the only way to spread the alarm, but it no doubt was expected to give the British some pause and for them to expect that some sort of resistance would be mounted against them.

Palin had just heard the facts from a pro, so they probably were pretty accurate, her problem was that she was determined to turn it into some kind of commercial for her right wing loony NRA pals and her agitprop machine simply fell into the automatic bullshit mode these people seem to shift into when they wrap themselves in the flag and claim only they have any patriotic right to do so.

As Robert once pointed out on this board, these people haven't earned the right to lick the horseshit off the founders' boots.