I'm a LEO Firearms Instructor and one-handed malfunction drills is part of the qualification I have my shooters run through.
1) "Clean" rear sights are a problem, its easier to hook a squared rear sight on a duty belt, boot heel, anything, etc. For those shooter that have the clean sights, then they are instructed to try and use the rear sight. Getting in the middle of a gun battle and having to do this one-handed is not the time to find out your sights aren't the best for this drill.
Choose your sights wisely!!!
2) After locking the slide, the shooters are taught to hook the magazine on the duty belt, etc and rip the magazine out.
Again, if your going to want to do this drill, then you better be practicing it. If you can't do it (with your equipment) then you might want to change it.
All my LEO shooters are required to draw, fire and clear malfunctions one-handed (both strong and weak hand).
I've done it using my Sig P-220, Beretta 92FS and S&W 6906.