Good question. I'm not going to quite call this one an errata - almost, but not quite. I have, however added a note to clarify the question in the mock exam.
In general, the questions on the real exam will tell you what you need to know, and in this case the question would have said that assertions were enabled. On the other hand, the general rule for the real exam is that if something is not stated explicitly, assume it's working. So things like correct compilers and JVMs and classpaths and imports, and command line invocations and stuff should be assumed to be correct if they're not listed explicitly on the question.
So for instance, if you see a code snippet without the entire class listed, you can assume the import statements are correct.
On the other hand, if you see a complete class listing and you think an import statement is missing, that might be the key to the question.
Does that make sense?
Spot false dilemmas now, ask me how!
(If you're not on the edge, you're taking up too much room.)
Sorry for a little off topic... I see you are working hard all the time and think you would be very dissapointed if you scored less than 100 % I belive you can achieve that score! Do you remember our classpath questions? They can be difficult, I had problems with one though I thought I knew everything about it after all our discussions As you know I passed SCJP at the end of March and plan to take SCWCD next month, hurry up man, coz I'll get another one before you get your SCJP... just teasing!!!
Let me know after you take the exam and how you did! Good luck!