moral dilemmas have no stakes
it’s easy to say the right thing to do when faced with a moral dilemma since you have no stake in the outcome. This is especially the case when the moral dilemma is simplistic, or set up like a moral temptations.
Predictive Scenarios to Explore Ethical Dilemmas cites Bandura 1999 in saying that answers to moral dilemmas to not predict actual ethical behavior.