Nope, you are confused about the meaning of cam-out. Flat head is actually significantly less likely to cam out than pretty much any screw fastener type besides inverted hex (allen). Cam out is when the torque applied acts to ramp the driver out of the fastener. The problem with flat head is that drivers do not self center, making them poor choices for power tools. There's a reason flat head screws are still used extensively in firearms manufacture, and it definitely isn't a manufacturing convenience. Carefully driving a flathead screw is much less likely to damage the finish of the fastener, provided the correct driver is used.