The point for #1 is that PIDs are reused. Just because the cron job previously started a process with a PID 473 doesn't mean that PID 473 is that same process the next time the cron job comes around to check. It's entirely possible that the original process was finished or killed and a new process started with the same PID.
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The point for #1 is that PIDs are reused. Just because the cron job previously started a process with a PID 473 doesn't mean that PID 473 is that same process the next time the cron job comes around to check. It's entirely possible that the original process was finished or killed and a new process started with the same PID.
This is why I also store the creation time to avoid reused PIDs.