Apple Watch app : Downloads only partially play

Observed:

Some podcast episodes in the Downloaded section in the Watch app will only partially play. It appears as if the download did not actually complete, but the Watch app is unaware of this and indicates that the episode is fully locally available.

Expected:

When the Watch app indicates that an episode is available locally in the Downloads section, the episode should be fully playable.

Start by reproducing the issue in the Apple Watch app with an episode from the Downloads section that only plays partially, then trace how local availability is reported. Done means an episode marked as available locally is fully playable.

Written by the indexing model from the issue text.