If you notice that the Corydoras has two asterisk marks beside it, then to the right is a disclaminer "**WARNING: Corydoras catfish are one of the most dangerous fish to keep with your frog they have spines which can choke the frog if it decides to eat the fish. I have Corydoras listed on this site because I personally have not had any problems with them, but thanks to several emails I now know other people have. If you choose to keep them it will be at your frogs own risk."

In the future just plan ahead any additions for either fish or frog tanks. Do the research ahead of time and don't give in to any impulse buys. Pet store employees have one objective - to sell. Don't take their word on most suitable tankmates. The don't recommend schooling/shoaling sizes, buying tanks for adult sizes of fish etc etc. Fish in the petstores, unless returned by a previous owner are mostly babies. People seem to think they stay that size and run into a lot of overcrowding issues.
On many of my fish forums the main time people experience problems is due to incompatible tank mates.