The weather was so bad that there were shadows on the ground...
lots of jobs are done without going to tender. The military aren't the only people that can jump at a moments notice, it happens for fires around the world, and numerous other operations. And while in the UK the standard call might be to the RAF, in other parts of the world the phone goes and a helicopter can be in the air very quickly...
lots of helicopters crash, and lots of people die. if we eliminated every risk we would never get off the ground, and pretty sure that the Airforce manage to crash just as well as the rest of us...
A true risk assessment on that operation wouldn't have a chinook hovering within a few feet of an extremely unstable dam with all that weight of water behind it. You could possibly say that a small helicopter would be better as it would create far less downdraft and pounding on the dam wall.
You would also say that they should have extended the lines by at least a few meters to keep the machine further away from obstacles.
so please don't continue with the RAF never does anything wrong and civvies don't know how to do anything crap. We are all capable of doing good work and we are all capable of crashing and killing people, quite often through stupidity...