Looking at the sunk cost materials, the answer to question 10 in booklet 1 seems a bit off:

Question: Sandra is starting to grow bored with her current boyfriend. Is it time to move on? She left her job in Los Angeles and moved to New York, just so that she could be with him—but they haven't had a really interesting conversation in months.

Answer: Sunk cost yes, sunk cost fallacy yes.

The time and effort it took to move are already gone and not coming back. Sandra's old job is already gone, also.

Sandra is acting as though her past costs are relevant to her present decision.

I would have marked this as "sunk cost yes, sunk cost fallacy no". The way I read it, Sandra's sunk cost of her leaving her job and moving is mentioned as background information, but it's not stated that Sandra would consider this to be a reason to stay.