Maybe you missed the culprit but they left you with a very interesting and unique subject! I think you could magnify the unique beauty of the flower by square cropping the image to have the flowers fill the frame. No matter what this is a great capture, superb depth of field!
Oh, no! Well, you ended up with a fantastic capture of their mess so at least you can feel good about that. I'm sure that was quite frustrating, though. :-(
The snails had a good feed and left there poos behind...