I agree entirely. Last night there was another student had someone breakfall on her head as well. The class was fairly energetic with very big flowing movements. We have a fairly large dojo, so normally this wouldn't be a problem.
I myself was thrown by a VERY experienced Sandan, the guy whose foot my head collided with was a visitor (4th or 5th Dan), being thrown by another Sandan.
I spoke with my partner afterwards and he suggested I protect my head with my hands/arms when doing a backward breakfall in future (obviously not always possible, but still, can't hurt).
Whilst I'm the first to admit that my ukemi isn't the greatest, I went where I was put. It seems to me that people get over-involved with what they're doing and forget that there are others in close proximity. People need to be more aware on the mat and follow the simple safety rules that we supposedly have -ie. always throw towards the outside of the mat.