Oh man, that's brutal. So the yellow leaves were the only warning sign? Did you check the soil moisture before they all fell off? Those things are so picky about water. Like, did it get too dry or maybe stay soggy? And where was it sitting? Light makes a huge difference.
Nah, yellow leaves are a terrible sign for anything. That plant was probably doomed from the start no matter what you did. People overthink the water and light stuff way too much.