I am no pilot, so forgive this “ignorant” question. If the aircraft was a 25,000 ft, how could that be a bird big enough to see like that? I thought the O2 above 10k feet was too thin to breath.
I understand if I am going east at 500 miles an hour, and something passes me at 500 miles an hour, it will look like its going a lot faster.
They saw something. I doubt at that altitude they were seeing a bird large enough to track.
Video released by someone calling themselves Stars Academy.
It looks like a Hollywood produced fake video to me. Dubbing voices over the real video footage. The remarks, supposedly by the pilots, are not what you would expect from experienced military officers but rather it sounds like something from a bad movie script writer.
As you said, the altitude of the aircraft is almost 5 miles above the ocean. It would be difficult to spot a bird at that distance.
As for your question about breathing above 10,000 feet, military pilots all have oxygen masks that supply needed oxygen which is produced by equipment on board the aircraft.