I think it depends on what kind of mistake it is. This post on Law School Expert Blog might be helpful to you: http://www.lawschoolexpert.com/comments-errors/
I believe it first appeared in PT57. Here is the list by PowerScore up until 2016: http://www.powerscore.com/gamesbible/logic-games-rule-substitution/index.cfm
(June 2009 LSAT = PT57)
... about this decision here: http://www.abajournal.com/news/article/ABA_legal_education_council_rule_change_end_admission_test_requirement?icn=most_read ...