They had multiple days there, capturing footage which they would have checked was valid over and over again to ensure they had footage for their articles. Indeed I can't think of anyone who would not have checked the initial footage to ensure the equipment was working at all, especially when working with a brand new device.
I can't fathom how it's remotely possible they did not know what was happening here, right from the start. In my opinion this was an attempt to make the XBO footage appear better than it actually is in comparison, and hope as many people as possible would just accept it as is. The article just seems to grudgingly admit some aspects of the PS4 version are a little bit better, but in no way offers a fair comparison we are seeing from other sites.
On top of this they then wrote an article using all this garbage footage, and instead of ensuring that they informed all readers in the very first paragraph that it was all messed up and they would be re-doing it fairly as soon as possible they went with what they had and created the side by side comparisons? Instead there was a brief mention that there might have an little issue with 'something', but don't worry nothing important. Oh please...
Luckily they got called out on this quickly, but it's nothing new for them, and strangely every time they screw up like this it always makes the Microsoft console look better in comparison to competition? There is also a history of not admitting to mistakes when they have clearly messed up. (deliberately of not)
I'm not getting either console as I can't afford one till next year, but it makes me sad that so many other people(not fans who will always buy only one brand) are going in to this not having enough real information about these consoles to make an informed choice.