Obviously he or she did a good job in sending you to this particular firm because you did receive an offer. I think your first mistake was not acting like an adult by doing your own negotiating. You put your recruiter in a difficult position by sending him or her out as your emissary to ask for more money and a bump up in class year. You should have been over at that firm thanking them for the offer and telling the partners how excited you are about the opportunity before you started asking for special consideration. Without doing your own bidding, the recruiter could not possibly be able to properly express your interest and enthusiasm.
Recruiters frequently do the salary negotiations because that is part of our job.
However, as I have discussed previously, that is only effective when the candidate has already spoken with the potential employer to say they more than likely intend to accept or, at the very least, that they are excited about receiving an offer. Since the major law firms historically pay their associates on a lock-step basis, there could be no possible way to ante up that kind of an increase even if they did bump you up one class year. With that in mind, it is understandable that they would think you were interested only in money and not in the firm and its practice, and therefore why they came to the conclusion that you would not be happy with them. As a third year associate, your job is to service the partners' existing business in the intellectual property department. Your technical degree is the important aspect for their needs at this time.