Recently, there are some tests<1> on the upper limit of speed of light. The test conducted by Zhang et. al showed that single photon still obeys speed limit which is the speed of light no matter in normal material or fast material. <1>Shanchao Zhang, J. F. Chen, Chang Liu, M. M. T. Loy, G. K. L. Wong, and Shengwang Du, "Optical precursor of a single photon," Phys. Rev. Lett. 106, 243602 (2011).
And yes, it was reverted, with the comment "Poor wording. Perhaps someone with access to the source can cast this into proper English?". (As always with text-only communication, it's possible to read-in some snark, where none is intended). I don't get the impression that this little factoid would have greatly improved the article, but the poor wording would have degraded it.
The correct call I think.
Edit: formatting
It's not even that bad.
There have been problems with the speed of light article that required arbcom measures; edit wars with a lot of talk page and ANI discussion, with some bans for users.
It's not a surprise to me that edits to the speed of light article get reverted.
If this holds true for Wikipedia it'd make sense to see more rejections than fixes. Let the person submitting it fix it. It's their problem.
The fact that a coordinated gathering of actual physicists working together on these pages had anything reverted is a telling example of the poison that will eventually kill Wikipedia.
Without a coordinated list to see just which edits failed to stick I'm not able to completely back my assertion. However I doubt that these people, working in groups where they have many eyes proofreading and spellchecking at once, were submitting the kind of changes with typos or other mistakes that would be understandably rejected by Wikipedia.