You would think that sabotage on the ISS would be easy to track down. Swapna Krishna:
Last Thursday, NASA informed the public that there was an air pressure leak aboard the International Space Station. It was extremely small and posed no immediate danger to astronauts. Flight controllers worked with the astronauts to determine that there was what appeared to be a drill hole aboard an attached Soyuz capsule that the astronauts attempted to patch. Now, the Russians are investigating sabotage as a possibility.
The facts in evidence range from outright sabotage to a horrible mistake to sloppy construction. Take your pick. Sabotage makes for a better story.