Live speaker numbers are a guess made as the audio arrives, and two voices can share a number. hark-viewer relabel fixes them once the call is over. A line that spans two offline speakers gets the one it overlaps most, because splitting it would need word timings transcript.json does not carry.
Speaker numbers start over in every part of a restarted call, so Speaker 1 before a restart and after it can be two people. relabel covers part 1 only. transcript.final.json avoids both, because it only tells Microphone from Others.
hark-viewer quit used to kill every hark process. It now kills only the remote-control agent, so an offline pass still running for the last call survives it.
Relabelling is manual. Most of its ten seconds goes on the recognizer producing text the relabel then throws away, because hark has no way to diarize a file without transcribing it. A hark speakers -i FILE would make this near instant.
A line appears when the speaker pauses for about 0.7 seconds, or after 12 seconds of unbroken speech. Those two values are fixed inside hark.
hark records one microphone, the macOS default input.
Clock times drift by the length of any pause, because hark leaves paused time out of the recording.
Recording a call needs the consent of the people on it. The rules depend on where you and they are.