This was identified as an action item during the postmortem review 20180229-Train-1.31.0-wmf.27.
Essentially what we discussed is that some changes are inherently risky and should be released more cautiously. The SWAT deployment process addresses this need for changes which happen throughout the week, however, some changes don't make it into a SWAT and instead they go out with the train. The weakness is due to the fact that the train deployment process does not alert key people when their patch is being deployed. So instead of having an alert developer on hand to test a patch as it's being deployed you have the situation where deployers have to track down the cause of errors and then attempt to contact developers who are knowledgeable about the changes in question. The whole process is awkward and time consuming.