IBES "actuals" data are the values that were reported publicly on the given date; they are not retroactively changed due to a subsequent restatement (for example, a restatement of actual EPS due to an accounting error). The actual values are "as reported" and not "restated".
Note the distinction between restated data (due to accounting errors or changes in accounting technique) and adjusted data (for stock splits). The Detail History Actuals data are adjusted for stock splits, while the Unadjusted Actuals data are not adjusted for splits.
An excellent reference paper describing the differences and similarities between actuals EPS in Compustat and IBES is a paper by Livnat and Mendenhall (Journal of Accounting Research, Mar 2006). You can also find more details on how IBES reports actuals can be found in the WRDS Research Presentation 'Overview of Thomson IBES'.