I also took my OPA today, and as someone who scored 2 wrong on my test, I also found the memory portion surprisingly difficult. Not too sure what they were scoring in the 2nd part of the exam, but assuming you aced it, should be allowed to get 6 or 7 wrong in the memory portion. I am confident most of you passed.
Of course, I was under the impression that as long as you pass the OPA, your OPA score would not affect your list number. Can anyone in the MTA confirm this?