Or can a human at AdWords disable keywords regardless of CTR?
I would say they do, there's no other way to explain it sometimes (unless Google have a "random ban" part to their algorithm to keep us scared) .... Google of course would say:
"Thankyou for raising your concern, please know that here at Google we take all of our customer's queries seriously. Google is based on algorithmic solutions to problems and we prefer to solve these types of issues ... blah, blah, blah ... beat around the bush some more ... talk about something else to distract you ... and then not answer the question directly."
When keywords get disabled, is that completely algorithmic? Or can a human at AdWords disable keywords regardless of CTR?
bakedjake, disabled keywords are purely algorithmic - and no, a human being can not cause a keyword to be disabled. This happens when the keyword has not met the minimum performance standard.
However, keywords can also be disapproved, and this is done by a human being during the review process. This happens when there is something about the keyword/ad/site combination that is not in line with policy.
AWA