Helen: It was wrong of my brother Mark to tell our mother that the reason he had missed her birthday party the evening before was that he had been in a traffic accident and that by the time he was released from the hospital emergency room the party was long over.
Conclusion (it was wrong)
It was wrong for Mark to tell mom that he missed her party because by the time he got out of the ER after his traffic accident, it was too late.
Evidence
It was false for him to say that.
And saying something that is false can never be anything other than morally wrong.
Evaluate
The final two premises don't really give us any way to argue with the logic. We know Mark said something false. They provide a conditional rule that says, "saying something false is always morally wrong". So then, didn't the author successfully prove her conclusion that what Mark did was wrong?
There isn't actually any way to argue that the premises don't imply the conclusion.
Goal
We might just have to check out the answers here, since our training would leave us unprepared for this moment. There's not any gap in logic between the evidence and the conclusion, and yet they're asking us how the argument is flawed. Hmmm ....