Eclipse Kepler (4.3.2) でも同じ動作をします。
次のシグネチャを持つメソッドにバグがあることがわかりました。
void get(Object o)
Object get(Object o)
Eclipse のエラー ログビューで、次の例外を見つけました。
java.lang.NullPointerException
at org.eclipse.jdt.internal.core.search.matching.ClasspathSourceDirectory.directoryTable(ClasspathSourceDirectory.java:52)
at org.eclipse.jdt.internal.core.search.matching.ClasspathSourceDirectory.findClass(ClasspathSourceDirectory.java:109)
at org.eclipse.jdt.internal.core.search.matching.JavaSearchNameEnvironment.findClass(JavaSearchNameEnvironment.java:146)
at org.eclipse.jdt.internal.core.search.matching.JavaSearchNameEnvironment.findType(JavaSearchNameEnvironment.java:185)
at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.askForType(LookupEnvironment.java:145)
at org.eclipse.jdt.internal.compiler.lookup.PackageBinding.getTypeOrPackage(PackageBinding.java:197)
at org.eclipse.jdt.internal.compiler.lookup.Scope.getTypeOrPackage(Scope.java:2799)
at org.eclipse.jdt.internal.compiler.lookup.Scope.getType(Scope.java:2556)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.getType(MatchLocator.java:899)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.getMethodBinding0(MatchLocator.java:955)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.getMethodBinding(MatchLocator.java:907)
at org.eclipse.jdt.internal.core.search.matching.MethodLocator.matchMethod(MethodLocator.java:327)
at org.eclipse.jdt.internal.core.search.matching.MethodLocator.resolveLevel(MethodLocator.java:664)
at org.eclipse.jdt.internal.core.search.matching.ClassFileMatchLocator.locateMatches(ClassFileMatchLocator.java:209)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.process(MatchLocator.java:1699)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.locateMatches(MatchLocator.java:1143)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.locateMatches(MatchLocator.java:1184)
at org.eclipse.jdt.internal.core.search.matching.MatchLocator.locateMatches(MatchLocator.java:1301)
at org.eclipse.jdt.internal.core.search.JavaSearchParticipant.locateMatches(JavaSearchParticipant.java:95)
at org.eclipse.jdt.internal.core.search.BasicSearchEngine.findMatches(BasicSearchEngine.java:231)
at org.eclipse.jdt.internal.core.search.BasicSearchEngine.search(BasicSearchEngine.java:515)
at org.eclipse.jdt.core.search.SearchEngine.search(SearchEngine.java:584)
at org.eclipse.jdt.internal.corext.callhierarchy.CallerMethodWrapper.findChildren(CallerMethodWrapper.java:155)
at org.eclipse.jdt.internal.corext.callhierarchy.MethodWrapper.performSearch(MethodWrapper.java:301)
at org.eclipse.jdt.internal.corext.callhierarchy.MethodWrapper.doFindChildren(MethodWrapper.java:232)
at org.eclipse.jdt.internal.corext.callhierarchy.MethodWrapper.getCalls(MethodWrapper.java:84)
at org.eclipse.jdt.internal.ui.callhierarchy.DeferredMethodWrapper.getCalls(DeferredMethodWrapper.java:65)
at org.eclipse.jdt.internal.ui.callhierarchy.DeferredMethodWrapper.fetchDeferredChildren(DeferredMethodWrapper.java:79)
at org.eclipse.ui.progress.DeferredTreeContentManager$1.run(DeferredTreeContentManager.java:235)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)
結局、このバージョンのバグのように見えます:
https://bugs.eclipse.org/bugs/show_bug.cgi?id=401272
少なくともバージョン 4.4 (Luna) にアップグレードすると、この問題は解決すると思います。