CaptureResultCallback doesnt return anything

I have the code such as this

CaptureResultCallback<Boolean> callback = new
CaptureResultCallback<Boolean>();
List<Object> eventContext = new ArrayList<Object>();
if (context != null) {
eventContext.addAll(Arrays.asList(context));

eventContext.add(value);
this.resources.triggerEvent(UPDATE_EVENT, eventContext.toArray(),
callback);

Boolean isSuccess = callback.getResult();
if (!isSuccess) {
formFlowEdit.recordError("Unable to save value");

As well as

@OnEvent(value = Edit.UPDATE_EVENT, component = "a")
public boolean inSaveEvent(String o) {
a = o + " yap it is saved 1";
ajaxResponseRenderer.addRender(zone);
return true;

Now everything runs ok (ie the value is properly propagated and all of
that). However I just cant seem to get a valid result back. My result value
(ie 'isSuccess' ) is null.

What am I doing wrong here? Any ideas?

Thanks