An action that times out, does not notify you, and does not abort the macro, is not considered an error. It is considered to be doing exactly what is expected of it. So it is not reported in the log.
Well, I'd say that depends. For example, one might include some actions they don't normally expect to timeout, but if some abnormal conditions occur, the actions do timeout (so that the macro doesn't hang).
But I can also see your point, @peternlewis. And since the current behavior is not going to change, one could modify the macro as follows:
Huh, I see it differently. In my eyes an "abort" is always an error / unhappy path, and I would expect all errors to be logged. I turn off notifications because the error doesn't merit being addressed immediately. The macro in question just does some nice-to-have system stats collection, and it's fine if it fails for a few days. I'm glad I wasn't interrupted, but I do wish I could have found more detail about the failure in the log file once I went to look.