Apologies for any noobish mistakes, but I am both new to this forum and new to keeping aquatic clawed frogs; I'm more of a poison dart frog guy myself.
Yesterday I bought a pair of Hymenochirus curtipes from a store that was keeping them in tiny "Eco-aquariums", which were less than one gallon, had a gravel substrate, and one plastic plant.
They were being kept in pairs, and I bought two of them. I brought them home and decided to keep them in the tiny aquarium until a bigger aquarium was complete.
This morning I found one of them bloated, floating on its back, and unresponsive. I figured it was dead until it started moving around.
A few hours later, it was laying in the corner, completely unmoving and has not moved for over 10 hours. I am now more or less certain it was dead.
I did a bit of investigation and found that it seems to have some form of bloat.
I pulled the surviving frog and put it in a bowl with clean spring water, the way I would treat a small fish. The dead frog is still in the tiny aquarium.
I have a few questions. Did this frog have bloat? Is it contagious? Should I keep the surviving frog isolated? Is it fine in its current QT, or should I move it?
What do I do here?

Here are some images, if they help:

The frog yesterday:
Name: Bloated ADF.jpg Views: 940 Size: 54.8 KB

The dead frog:
Name: Dead ADF.jpg Views: 847 Size: 74.2 KB

The survivor in the bowl which I am using as a temporary QT:

Name: Survivor.jpg Views: 578 Size: 60.3 KB

P.S.
Once again, I apologize for any stupid mistakes I may have made. Maybe I was so excited to start collecting ADFs that I didn't notice that the frog or frogs weren't healthy.
If i'm an idiot, don't criticize me, just tell me if I'm doing anything wrong.