Frogs have been known to eat hummingbirds. Maybe it was the frog's karma?

Neat frog story got related to me tonight when I took an old friend out to dinner who I hadn't seen for awhile. Said friend had raised a couple of tree frogs he had grabbed from his backyard when they were tiny. This summer he grabbed another couple of tree frogs to raise and observe, and as they are doing well in the aquarium, he decided earlier in the summer to liberate the first two. One of them frequents the water garden. (He knows it is one of the frogs he raised because, due to the constant good diet of crickets they got in captivity, they grew to a bit larger size than tree frogs in the wild achieve.) Two weeks ago he was sitting on the steps of his deck, near the water garden, and the tree frog jumped down onto the ground, and hopped toward him. To his amazement, the frog hopped up the steps and then onto his leg, and sat there looking up at him for quite a long time before finally turning and heading back into the yard and up into a tree.

His best guess is the frog recognized him by sight or smell as the source of live crickets tumbling into the his previous aquarium home at regular intervals.