This thread is a really good illustration of why I don't use evaluative metering unless I have no other good options available to me.
Evaluative metering is a "magic" metering mode. Nobody really knows how it works, because it's the metering mode that tries to automatically get the exposure right. And just as the camera will occasionally (and perhaps even often) get it wrong if you let it choose the autofocus point to use, it will occasionally (perhaps even often) get it wrong if you let it automatically decide how to meter the scene.
This is why I generally use one of the other metering modes. Most often, I use spot metering in conjunction with manual mode because it lets me set the exposure based on the tone I want to assign to the area under the spot meter. It's about as much direct control as you can get.
I understand why Canon has evaluative metering mode as an option -- it's useful for neophytes who don't know anything about exposure. But I actually find it a bit surprising that it's used by professionals as often as it is. I suppose, like anything else, that once you have enough experience with it, it becomes predictable and, thus, useful in a setting where you must get the shot right. But because it's a "magic" mode, Canon is constantly tweaking it as they introduce new models, so you can expect to have to re-learn everything about it when you move to a new camera model. And this thread is evidence of that.
I really wish Canon would give us focus-point-linked spot metering in these cameras. It would eliminate most of the situations where I would be inclined to use evaluative metering mode (e.g., tracking a subject through changing light).
Canon really should at least give us one more metering mode: focus-point weighted average, which would work exactly as center weighted average does except the weighting point would be the focus point instead of the center. That would introduce a lot of predictability in a metering mode that would otherwise behave quite a lot like evaluative.