It was firmly attached. The battery is sticky-taped in place. It can’t move or be jostled no matter how much the player is banged around. Trust me, it’s dead. The battery “case” is just pressed foil crimped around the terminals. Keeps the bulk down but the result is a fragile power storage unit that just can’t handle a simple run through a washing machine. :)
There have been a large number of people here whose players have gone for a swim. Those who don’t immediately try to turn it on (and consequently short it out for good) have had good success in reviving it by drying it out thoroughly either by letting it air-dry (open or closed) or by sealing it up in a bag with a desiccant like white rice for several days.
We haven’t heard of any where the battery was completely hosed by the experience. More likely is the possibility that there is some residual moisture somewhere on the circuit board, or minerals and/or soap suds that are providing a electrical conduit between 2 adjacent solder points effectively preventing it from powering up.
Although it sounds counter-intuitive, a good thing to do would be to take it for a few more laps in some distilled water to throughly rinse out any residue from the wash cycle and flush any conductive minerals away. Then . . . give it a good drying-out.