attempts to justify a judgment about a particular case by citing a general principle that stands in far greater need of support
Why this is right
The author is making a judgment about a particular case (it was wrong for Mark to tell my mom that ER story). She does cite a general principle as part of her support: saying something that is false can never be other than morally wrong This answer is saying, "Don't worry about the conclusion (the particular judgment). Worry more about that crazy principle you're citing. Who says saying something false is always morally wrong? When I ask my 5 year old what 8 + 9 is, and she says "15", she has said something false, and thus she has done something morally wrong? When she asks me if her drawing is good and say yes (even though it's not), have I done something morally wrong? There's a huge gap between saying something false and being deliberately dishonest in the lying sense. This is a very unique question in LSAT's canon. There have been 3-5 Weaken questions ever that seem to basically contradict one of the premises or just hurt the argument by making it seem like the premise is just bad data. But this is the only one I've ever seen where they seemingly wanted us to just complain about a bogus premise. We can be forgiven for not noticing, but the question stem doesn't ask the typical version of Flaw, which says "the argument/reasoning is most vulnerable to criticism for what reason". Instead, it says "the justification (the evidence) is most vulnerable to criticism for what reason".
Skill tested: Flaw · how this choice captures the argument's function is the move to repeat next time.