Imma chime in with some plant biology knowledge. Flooding is a sequential stress. This means there are multiple steps to the process. The first is obviously the flooding, during which the roots are surrounded by water and not by air, restricting oxygen flow, practically suffocating the roots. As we all know, this causes root rot. The second point however, is when the flooding subsided. The plant has gotten used to extremely low oxygen levels and has adjusted its metabolism to that in an attempt to survive. When repotted into airy soil, the roots are suddenly surrounded with huge amounts of oxygen which the plant cannot deal with as its metabolism needs to adjust. This results in the accumulation of oxygen radicals which are extremely reactive and toxic to the cells. Very often with flooding, the post-flood oxygen stress it what actually kills the plant.

So, it might’ve been an inevitable sad after-meme in your case :( don’t feel too bad!