I had something similar happen to me. I was taking a picture of an iris in Louisiana when a hummingbird flew into view. I couldn't react fast enough to get the picture, either.

Another time, I was sitting on a sandy beach in the Grand Canyon, wearing a floppy hat with flowers printed in it, when a hummingbird flew up to me to check out the flowers. I didn't see the bird, but I certainly heard its wings, and I saw its shadow on the sand. In a few seconds, it was gone.