Hello,
DirAuth's can cache multiple versions of the descriptor and serve what appears to be the newest in a given consensus interval. This coupled with routers publishing descriptors at least every 18 hours, but potentially sooner. What you describe doesn't appear to be a bug in Onionoo because a consensus exists for which the family is declared as you describe in the last known good descriptor.
At the moment you describe Atlas doesn't show:
[1] last published 2015-06-02 17:44:27 (and [2] may still have entered hibernate) [2] last published 2015-06-02 09:40:45 (and [1] may not be running, or have a last known good descriptor at DirAuths)
This doesn't take into account the possibility of a router hibernating (info not always available) at times between consensus taken or valid. A router can be running but unavailable due to accounting. This looks like a result of cached descriptors or router accounting. The data provided to Onionoo from metrics-lib appears accurate as far as network status. At least that's how it looks from a preliminary glance at the data and spec--although please do your own verification.
--leeroy