I think you reacted well. You can't always go by what others are doing (or not doing), but without follow-up sounds or visuals, I'm glad you didn't run screaming down the street, starting a panic.

I grew up with sonic booms. I thought they were sonic booms *shrugs*, maybe aircraft from Ft. Lewis/McChord playing around. Their humongous whup-whup-whup helicopters fly over my house fairly frequently, sounding about five feet above the trees.

I guess it scared a lot of dogs, though.

Sue