I apologize if I came across as condescending- that wasn't my intention at all. I just hear so often of people buying fish at Walmart (I've done it myself!) and being misinformed by the store personnel of their needs. Cories look cute, so people buy one for their tanks without knowing what they need, same with bettas, clownfish, etc. I didn't know what had happened to your tank based on your first post. Just wanted to make sure that the cory was okay. Forgive me for being an obsessive animal lover?
Sorry to hear about your lost fish while you were on vacation! So sad!