I've never posted on a bulletin board before, but the tone of your posting sounded both sincere and concerned, so here goes. I apologize in advance if this is too long or rambling.
As an introductory note, please understand that I am not an Aikido "expert." However, I have 8 years experience in Aikido and 20 years experience in Shotokan Karate, and I've lived long enough that I've seen the scenario that you desribed a number of times.
My advice is to chalk it up as a learning experience, stop worrying about it, and move on with your training. It sounds to me like the senior student let his/her ego get out of control (which happens to most of all of us from time-to-time). That, combined with your escalating frustrutation (which also happens to most of us from time-to-time), was a volatile combination. Frankly, I think that you handled his/her "threat" to hit you much better than I would have handled it.
If the situation arises again, I'd suggest stating very on, "Thanks a lot for the advice, but I'm the type of person who learns by working all the way through a technique, so I'd really just prefer to press on for a few repetitions before discussing it." If it persists, I'd raise the response a level, stating in a calm, measured tone, "Thanks again, but I know myself well enough to realize that I've just got to work on this technique without any external feedback. No offense, but I'll just focus on your feedback instead of the technique. Thanks for understanding." If it then continues, I'd say that the person is either unusually dense, or is intentionally trying to escalate the issue. Either way, I'd just bow, thank people for their help, get a drink of water, then work in with a new group. After class, I'd mention it to the instructor.
As an instructor, I'd want the student to raise the issue with me when there were no other students around, and I'd want them to raise it with me in a calm, objective fashion. Don't cast blame, just say the situation is troubling to you and you'd appreciate the instructor's assistance in dealing with it.
I hope that this is useful to you.