My Fujica ST 901 with its Silicon Blue Cell (SBC) has always been quite accurate. It will measure down to about 30 seconds at f/1.4. Very useful.
However, no reflective meter will give you consistant results in difficult lighting situations. It will be fooled if there is a preponderance of light or dark areas in the scene. That is when experimentation and experience come to our aid. Cameras all have reflective meters unless you put an accessory dome on them, move to your subject's location, and use them as an incident meter.
Alice, generally incident meters give better readings in the situation you describe as they are doing just what their name implies, reading the light incident on the scene, not reflecting from it. However, you example is again an extreme. you would likely have to compensate. At
http://www.butkus.org/chinon/luna-pr...luna-pro=3.htm you can read a short explanation of some of the differences and how a null meter can be of help. However, don't be discouraged if you don't have or don't want a null meter. Experience will allow you to do the same calculations for yourself.
And then there is always the possibility that your meter could be off up to 1 stop anyway.
EDIT: I don't know what has happened to the Butkus.org site. However, I notice this has become a busted link. Hopefully it will be back up soon for all those who manage to purchase a Luna Pro SBC and want to know how to use it. They are a really useful meter.