I noted in the other thread that if a particular quest stage is complete (only goes complete if you refuse to help them after rescuing the two prisoners) then a script will automatically kill Red and disable Timebomb. I don't see anything that prevents the rest of them from being resurrected, though.
Said script is what's causing the OP's issue. Since it checks to see if either of them are alive upon being triggered, the act of resurrecting either of them causes the check to occur again and the relevant kill action to be reapplied.
If this is, indeed, the case for the OP, then the only way to keep them alive would be to disable the script and that's probably not a good idea unless you know exactly what you are doing.