Why would performance timing data showing domComplete before connectStart and connectEnd?

I have a simple uncachable (Cache-Control: private) document which I'm recording timings in. When loading this document via clicking on a gmail link in latest Firefox, the resulting data is confusing. All of the dom-related timestamps are BEFORE the connection info. This happens consistently whenever I click on the link from Gmail, and I haven't been able to otherwise repro it.

Additionally, responseStart and responseEnd occur 300 ms after everything else.

Here is the performance data, as shown by the browser console after loading the document:

{
  "redirectEnd": 0,
  "redirectStart": 0,
  "unloadEventEnd": 0,
  "unloadEventStart": 0
  "domLoading": 1461369761934,
  "domInteractive": 1461369761968,
  "domContentLoadedEventStart": 1461369762003,
  "loadEventStart": 1461369762006,
  "domComplete": 1461369762006,
  "domContentLoadedEventEnd": 1461369762006,
  "loadEventEnd": 1461369762008,
  "navigationStart": 1461369762030,
  "connectStart": 1461369762031,
  "connectEnd": 1461369762031,
  "domainLookupEnd": 1461369762031,
  "domainLookupStart": 1461369762031,
  "fetchStart": 1461369762031,
  "requestStart": 1461369762031,
  "responseStart": 1461369762313,
  "responseEnd": 1461369762371,
}

Am I misunderstanding something here, or have I hit a bug with performance timing data in FF? The same thing does not occur in Chrome.

Thanks!