The assessor's reports are basically never wrong for psych. Roger Edwards definitely knows his stuff. So you can be confident that he's right.
You need to write an ethical principle which is being breached in the case study. Does it mention that the researcher revealed the identity of one of the participants? No. So you can't write confidentiality. You can't assume something just because it hasn't been explicitly stated. The ethical principle that wasn't abided by SHOULD be in the case study somewhere, so scan through it till you find something that fits. If you look you should see "were given extra marks for their course for taking part" or something like that. This doesn't follow the principle of voluntary participation. Hope that helps.
Does that include informed consent?
"Professional conduct or voluntary participation. The participants were coerced into taking part by being given extra marks for their participation.
Withdrawal Rights. There is no evidence that participants were informed of their rights to leave the experiment at any stage or to have their results eliminated after the completion of the research. This was accepted as correct, though withdrawal rights should be covered in the informed consent procedures that were carried out."
From the 08 assessors report for this question..
I thought confidentiality and informed consent were two different things, but don't quote me on that.