I re-injured a herniated disc exactly a year ago doing standing presses. Since actually being injured doing this exercise I'll give my input on this exercise.
This exercise is NOT dangerous if done properly. My mistake was doing a standing press for reps with something like 90% of my max (185 at that time) when my back was not properly healed. Talk about dumb, but you live and learn.
One year later I can do these with no problem, even after a herniated disc.
For me, the proper way to do these is to have a strong lower back, work with no more than 85% of my max and if I struggle to lock out just release back to the starting position. Struggling to lock out and fighting it up is where most injuries occur during this exercise (I think, that was my case though), most likely because during the struggle you may put your back in a vulnerable position.
Even after a herniated disc, I rehab'd and now hoist heavy objects over my head. It's nice to be young (25).