Yes, fish are opportunistic. Fish that don't normally eat other fish will take advantage of an easy meal. It could also be that the fish is hiding somewhere in a decoration. Check around.
Snails are about a 1/4" long so that not it and I searched around the tank as best I could without tearing it completely apart... Oh well, I was getting ready to pick up a few more anyways.
The MTS have only been in the tank for about 10 days. Saw one of them last night on the glass and it was tiny! They were hitchhikers from when I picked up some Panda Cory's.