The answer is in the same passage.
Acceptance, then, may be a passive and inevitable act, whereas rejection may be an active operation that undoes the initial passive acceptance. The most basic prediction of this model is that when some event prevents a person from "undoing" his or her initial acceptance, then he or she should continue to believe the assertion, even when it is patently false. For example, if a person is told that lead pencils are a health hazard, he or she must immediately believe that assertion and only then may take active measures to unbelieve it. These active measures require cognitive work (i.e., the search for or generation of contravening evidence), and if some event impairs the person's ability to perform such work, then the person should continue to believe in the danger of lead pencils until such time as the cognitive work can be done.
Depends on the individual. You evaluate the initial statement after comprehension/acceptance and choose how you wish to view it based on whatever criteria you want.
The default state is acceptance though, not neutrality, as is demonstrated in the experimental part of the paper.