George Dishman, November 19, 2017: "Of course they noted that there was still the possibility that some hacker had deposited the chirp in the database but that has become entirely academic. With the observation of the BNS merger in August this year, the proof that the LIGO system works as advertised is complete. It would not have been possible for a hacker to deposit that signal without knowing the location, distance and chirp mass of the event 12 hours before the first telescope found it from the directions given by LIGO. The FERMI and INTEGRAL telescopes could confirm that an event had occurred but only give a rough location in the case of FERMI and a broad annulus for INTEGRAL, and only LIGO has any way to measure the distance directly. The kilonova was confirmed by dozens of telescopes and watched for weeks by many depending on the wavelength of the emissions as the fireball cooled, but a hacker would have had to have all the details and inserted the corresponding waveforms within seconds of the nova happening, clearly that is impossible." https://www.researchgate.net/post/Am..._wave_GW150914

FERMI can give only a rough location? How rough? Actually FERMI (or GOTO) detected the event initially and informed LIGO about it. LIGO is unable to detect anything. Its detections (more precisely, fakes) are MODEL-INDEPENDENT, that is, LIGO conspirators don't use theoretically calculated waveforms in detecting gravitational wave signals:

The Nobel Committee for Physics: "While these waveforms provide a reasonable match, further important improvements are obtained using numerical methods that are very computationally intensive [23]. The analytical methods are crucial to producing the big library of template waveforms used by LIGO. While the waveforms produced in this way are necessary for determining the detailed properties of the objects involved, as well as identifying weak signals, they were not essential for the very first detection of GW150914. This was a model-independent detection of a gravitational-wave transient." https://www.nobelprize.org/nobel_pri...sprize2017.pdf

Rana Adhikari, professor of Physics at Caltech and a member of the LIGO team: "You split it in two and you send it in two separate directions, and then when the waves come back, they interfere with each other. And you look at differences in that interference to tell you the difference in how long it took for one beam to go one way, and the other beam to go the other way. The way I said it was really careful there because there's a lot of confusion about the idea of, these are waves and space is bending, and everything is shrinking, and how come the light's not shrinking, and so on. We don't really know. There's no real difference between the ideas of space and time warping. It could be space warping or time warping but THE ONLY THING THAT WE REALLY KNOW IS WHAT WE MEASURE. AND THAT'S THE MANTRA OF THE TRUE EMPIRICAL PERSON. We sent out the light and the light comes back and interferes, and the pattern changes. And that tells us something about effectively the delay that the light's on. And it could be that the space-time curved so that the light took longer to get there. But you could also imagine that there was a change in the time in one path as opposed to the other instead of the space but it's a mixture of space and time. So it sort of depends on your viewpoint." https://blog.ycombinator.com/the-tec...ikari-of-ligo/

LIGO and FERMI had already tried the hoax - optical confirmation of LIGO's "discovery" - but then INTEGRAL exposed the fraud:

"Integral is sensitive to transient sources of high-energy emission over the whole sky, and thus a team of scientists searched through its data, seeking signs of a sudden burst of hard X-rays or gamma rays that might have been recorded at the same time as the gravitational waves were detected. "We searched through all the available Integral data, but did not find any indication of high-energy emission associated with the LIGO detection," says Volodymyr Savchenko of the François Arago Centre in Paris, France. Volodymyr is the lead author of a paper reporting the results, published today in Astrophysical Journal Letters. [...] Subsequent analysis of the LIGO data has shown that the gravitational waves were produced by a pair of coalescing black holes, each with a mass roughly 30 times that of our Sun, located about 1.3 billion light years away. Scientists do not expect to see any significant emission of light at any wavelength from such events, and thus Integral's null detection is consistent with this scenario. [...] The only exception was the Gamma-Ray Burst Monitor on NASA's Fermi Gamma-Ray Space Telescope, which observed what appears to be a sudden burst of gamma rays about 0.4 seconds after the gravitational waves were detected. The burst lasted about one second and came from a region of the sky that overlaps with the strip identified by LIGO. This detection sparked a bounty of theoretical investigations, proposing possible scenarios in which two merging black holes of stellar mass could indeed have released gamma rays along with the gravitational waves. However, if this 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." http://www.esa.int/Our_Activities/Sp..._bl ack_holes

Apart from FERMI, GOTO conspirators could also have informed LIGO about the event. They didn't "react swiftly" to an information coming from LIGO so the opposite could have occurred - LIGO reacted swiftly to an information coming from GOTO:

"This is where the GOTO project comes in: it is set up to react swiftly to any indication of a possible gravity-wave event emanating from the LIGO and VIRGO facilities, point at the area of sky where the signal is believed to have originated, and look for any sudden changes."x http://optics.org/news/8/7/7

Pentcho Valev