It all began with this paper that was made public just hours after the announcement of the first detection of a gravitational wave on Feb. 11: the Fermi satellite had seen "a weak transient source above 50 keV, 0.4 s after the GW event was detected, with a false alarm probability of 0.0022" - which no one had predicted to accompany a merger of two black holes. A flood of papers followed within days ("Eine Flut von Papers zur ersten Gravitationswelle") trying to make astrophysical sense of the coincident signals. And there was also a paper on the non-detection of a gamma signal by the Integral spacecraft at the same time which its authors said killed the Fermi observation (in an updated version of their paper the Fermi observers immediately rejected that). So far all this debate had taken place in academic circles and on ArXiv only, though noted by a handful of science writers who actually follow scientific developments first- or close-second-hand.
One of the theory papers trying to explain the allegedly related gamma signal, however, was eventually hailed by the Center for Astrophysics in a Feb. 23 press release which led to several more media reports. But then came a counter strike by the ESA PR department with a press release on the Integral non-detection on March 30 once said paper had been accepted by the journal it had been submitted to. Way down in the text (under the 'fold' actually) the release stated that "if this [Fermi-reported] gamma-ray flare had had a cosmic origin, either linked to the LIGO gravitational wave source or to any other astrophysical phenomenon in the Universe, it should have been detected by Integral as well. The absence of any such detection by both instruments on Integral suggests that the measurement from Fermi could be unrelated to the gravitational wave detection." The arguments in the Fermi paper trying to fit the Integral negative as well were not discussed.
And now Strike Three in what has become a rare transatlantic battle of press releases: On April 18 NASA suddenly came around with a press release on the Fermi paper, now over two months old and apparently still not accepted by its journal. "Gamma-rays arising from a black hole merger would be a landmark finding," the text read, and the first author is quoted: "This is a tantalizing discovery with a low chance of being a false alarm, but before we can start rewriting the textbooks we’ll need to see more bursts associated with gravitational waves from black hole mergers." The non-detection of the signal by Integral and the - pretty adamant - claims by its observers that the Fermi result cannot be right (emphasized in discussions with this blogger, I may add), are not mentioned at all! And so the I'm-only-reading-press-releases faction of science churnalists is left in utter confusion - while everyone else is waiting for more concurrent LIGO and Fermi / Integral / etc. observations that should eventually settle the issue.