It was designed to be robust to any case.  The Log objects aren't created / started until the actual command runs (they use a Log-aware command object), so that's not a problem.  Tying things together in this way say that, if the job craps out and is not updated, the Log also will not.  And if it is updated, then it will.  In other words, this just keeps them in sync.

So, no particular scenario, but I believe it's a more robust choice over the alternatives (for example, embedding this only in the command code, which can be aborted with ctrl-C or kill).