I agree partially.
Depending on the type of interviewer you have, being short and waiting for another question may not be the best tact. We've heard several times now of schools that are conversational in an interview. I agree, in any interview, answer the question ask succinctly and stop. Do not ramble on about the topic, but if it is obvious that the interviewer is looking for a more conversational tone, ask a question back. After making your point, perhaps ask the interviewers op[inion on the same question or if the question is:
"what are you looking for in you fellow dental school classmate?" Answer, and then possibly ask the interviewer what his or her perception of the majority of student at the school are like.
As far as plagerism...it's a cut and dry topic. You tell them what you think...which hopefully is that you should not plagerize because it is stealing someone else's work...and then wait for another question that is more interesting