Sorry, I think there is come confusion here. I did not mean the link labeled 'Wipe Out Workspace' that is provided by Hudson but the actual feature of the Perforce plugin (found in PerforceSCM.java; see snippet below) that calls workspace.deleteContents().
If it helps, I can supply a patch as an example of what I'm doing here to work around this.
[ Code Snippet ]
if(processWorkspaceBeforeDeletion(build.getProject(), workspace, build.getBuiltOn()))
log.println("Could not clear workspace. See hudson.perforce.PerforceSCM logger for details.");
forceSync = true;