React-native: scrollview inside of panResponder

I am using a ScrollView inside of a PanResponder. On Android it works fine but on iOS the ScrollView will not scroll. I did some investigation and here are some facts:

1. If I put a break point in PanResponder.onMoveShouldSetPanResponder(), before I step over, the scrollView will scroll as normal but once I release the break point, the scrollView stops working.

2. If I modify ScrollResponder.js, and return true in scrollResponderHandleStartShouldSetResponderCapture() - it used to return false at runtime; and return false in scrollResponderHandleTerminationRequest(), the scrollView works OK but of course, since it swallows the event the outer PanResponder will not get the event.

So the questions are:

1. I want to make the scrollview to work, and not to swallow the event. Any one know what's the approach?
2. How the responding system works on iOS? The react-native responder system doc does not explain that to me.