Question regarding an incident during early aikido
I have a question about an incident that occurred recently at my dojo. I am a very new member of my dojo and the incident occurred during my fourth lesson.
The lessons this week were preparing students for belt exams to be held on the weekend. The dojo was more crowded than I had experienced the three times previously. The sensei went through the waza very quickly, and seemed determined to pack as many waza into each 2-hour session as possible. During my fourth attendance, eight kumi waza were practiced. During one of the waza, I was partnered with one of the exam students, and was thrown very quickly, in crowded conditions, and stepped on. I was then scolded by sensei for letting myself be stepped on.
We had one practice of forward rolling, and I did inform sensei that I had never done a martial arts roll before. That was it, my one practice, from a kneeling start. About few waza later, we were then to be thrown in a waza that required us to run at the nage, be thrown, and roll from a run. You guessed it, I did not catch myself correctly, but was unaware at the time that I had done myself any injury. Another newbie (this was his first lesson) landed badly on his knee and twisted it, in the same waza.
I went home with a torn scalp from having my hair stepped on, and later learned that I had sprained my neck. While I can accept my torn scalp as a hazard of martial arts practice, I don't feel at all good about my sprained neck.
I don't have any previous martial arts experience, nor anywhere else to go, as this is the only dojo of its kind in my location. I have friends who are sensei in other martial arts disciplines; they are very concerned that I was put into a class intended to prepare more experienced students for belt exams. Hence my question: Is that normal practice in any style of aikido, to have rank newbies participate in exam-prep classes? I feel very apprehensive of returning to the dojo, also very apprehensive of getting scolded again for something that I'm really not sure should be my fault.