Close Encounters With Giant Bullfrog

Yesterday was filter cleaning day for the large pond and I decided to also clean the waterfall to get ready for winter. I shut down the waterfall pump and removed the large Sweetflag that was in the waterfall pool. The waterfall pool is a 20 gallon reservoir and it was very murky. After removing the Sweetflag, I reached in to remove some rocks on the bottom and was shocked by something very large that squirmed around. After my shock subsided, I scooped out the water until a couple of inches were left and there was the largest Bullfrog I've ever seen up close. I captured him and put him in a bucket while I finished the cleaning. In this picture, you see the bullfrog almost covered the bottom of the bucket which is 8 1/2 inches across. After I finished the cleaning, he was returned but I worry he'll be unhappy with the newly clean environment.