That sucks. It's amazing how they can manage to get out of the tank with the smallest of openings. I found a platy on the floor by my tank a few weeks back. Assumed it was dead and went to pick it up and it started flapping around. Turned out to be fine so it must have just happened but that was a pretty lucky coincidence.
Sorry that it happened to you. RIP Chirp.
Animal testing is a terrible idea; they get all nervous and give the wrong answers.