Open the pod bay doors, Hal...
Okay, after Andrei was safely in the airlock and depressurized, why couldn't another astronaut suit up, get outside and attempt to save the other astronaut? Contriving some equipment to scrub him, and get him inside the airlock. They still had 20 minutes of air and anyway it's a movie, that's a long time in a movie. But then NASA astronauts can go out for 6-8 hours at a time, so why can the astronauts in this movie only go out for short times like 1-2 hours?
Naturally when he pushes Andrei into the airlock he goes flying the other way thanks to Newtonian Physics, guess he wasn't a Physicist, any High School kid could have put him right there.
Now although Hydrazine is toxic, it can be diluted and washed away with enough water. In a real emergency would it not be more probable that some of the crew retreat to a safe and sealed off area of the ship, while Andrei recovered to a point where he could then help remove the other astronaut out of his contaminated suit? After which they could exit the airlock and be treated for any exposure to the Hydrazine, the airlock could be physically cleaned and any tainted materials disposed of. Guess I'm thinking too deeply and logically for this movie...