Last modified: 2014-03-24 18:51:52 UTC
Flow\Contributions\Query returns contributions from all wikis, not just the local wiki. These invalid contributions are currently caught in the formatter and logged, they should never get to the formatter in the first place.
To be clear, contributions from other wikis could have caused exceptions on mediawiki.org but the Flow team caught this before deployment and with gerrit I0afcdcd5 changed them to log.
The WMF core features team tracks this bug on Mingle card https://wikimedia.mingle.thoughtworks.com/projects/flow/cards/739, but people from the community are welcome to contribute here and in Gerrit.