On a side note: Should he have been able to see whose results he was looking at? It's surely unethical in my book. Even when, or perhaps even more when, working with data from relatives the burden of ethical behavior lies with the researcher. De-anonymising shouldn't be the researchers option without safeguards imho.
Yes, researcher needs to be trained on ethics specifically. It is a part of psychological education, it is a part of APA's mission[1]. Psychology takes it seriously after Little Albert Experiment[2], Ash Conformity Experiment[3], Zimbardo's Standford Prison Experiment[4], Milgram Experiment[5] and a lot of others. Now it couldn't be done, a researcher needs to approve his experimental plan with APA Ethics Committee.
It means, that any competent researcher in a psychology would know ethical risks (due to education), and if he is testing his research plan on his family, he must be ready to find something unexpected, and he must inform participants on the risks.