Well, stack already handled the 40 second thing, but I'm not seeing how this swimming pool thing works. They're bouncing off the ring and doing flips and stuff. They're obviously exerting themselves quite a bit over the 25 second period and should be exhaling their breath to keep up that much exertion. You really think NASA can edit out the streams of bubbles?
It's way too grainy to make out any bubbles. Plus, the film is clearly slowed-down so the real-time needed to film it would be significantly less than the time it takes to playback. Also, notice how the guys run around the circle in Stack's video. How is that possible? Where is the normal force coming from that keeps the astronauts feet attached to the surface? In zero-g, intertia would cause them to move in straight lines opposite the line of force caused by his feet pushing down. This proves the video is fake.
ADDENDUM: The claim that it couldn't be faked using wires because they would have gotten tangled is sensible, but using multiple exposures they could have achieved the effect shooting each astronaut one at a time. If it was choreographed carefully enough the portions where the astronauts appear to come into contact could be made to look natural.
What's your evidence again that it's 'clearly slowed-down'? I don't see it personally, although more because there are bits that look odd at one speed but not the other, and vice versa. Interlaced frames =/= film speed difference. You'll need a better case than that.
As for running around in a circle, do you understand how moving in a circle works? You calling this impossible, imo, calls into question the rest of your concerns about this video. That's very simple physics going on right there. Go spin a bucket of water around on the end of a string. The force being applied is always towards the center, yet it doesn't ever end up there. Why? Same thing. (I'd also note your assertion that it's happening on a vomit comet would produce zero-g circumstances and render this a feat impossible there too, leaving you *required* to have wires which simply isn't the case)
The fact that this old footage is cutting it so close to the limit is evidence enough. It's not like 1970's video cameras could only record video for less than a minute.
Only if you're already inclined to think it's fake. Length of segments is not strong evidence in and of itself without entering with bias.