Fortunately, I'm pretty sure that the manipulations like the following don't need i18n:
  event_info['answers'][response.answer_id]
The data going into event_info is for the"logging" (is that the word we use?) data for later analytics passes. So "answers" is the key in some JSONish thing used the analytics. This PR actually has a significant analytics intersection, since the shuffling/subsetting/masking is all stuff that we want to record nicely, so that the later analytics people can keep doing what they're doing. I think @mulby was the reviewer making sure that analytics was getting what it needed.