Actually, in Columbus' time it was pretty generally accepted that the Earth was spherical. The real question was how feasible it would be to go the "long way around" it. Most thought that the voyage would be too long to be practical and/or safe, and would be open to too many unknown dangers. Columbus thought it would be practical and wanted to give it a shot.
The funny thing is that at the core Columbus was wrong -- the Earth was a lot bigger than the believed it to be, and what he thought was the "Indies" reached from the "opposite" direction than that usually used to travel to it, was actually an entire new continent blocking his way. And in fact, had North America not been there, he and his crew would have probably died of starvation and thirst before they circumnavigated the globe as they had originally planned.
And the theory of evolution, as it exists now, needs to be questioned.
And it is.
In fact, many thoughts about the theory of evolution have changed as people research and question. So why was it wrong for this professor to do so?
First, because I think it's pretty clear she wasn't just "questioning it", she was trying to undermine it in the minds of her students. Second, because a classroom is not the proper place to do such things (in that manner). If you're trying to challenge the orthodoxy, do it in the science journals and other forums, *not* the classroom. It's one thing to point out the "open questions" in a given field. It's another thing entirely to try to "convert" your students (in a science class) away from widely accepted scientific views.