UIA Event Handlers leaking handles

I have been testing a Microsoft supplied sample of a C++ IUIAutomationEventHandler program.
The link to the source code is https://docs.microsoft.com/en-us/windows/desktop/winauto/uiauto-howto-implement-event-handlers#handling-general-ui-automation-events.
I used Visual Studio 2017 to build a standard console application using the sample code on Windows 10.

After starting the UIA application, I then repeatedly started and stopped the Calculator program. The Windows Task Manager revealed that the UIA application handle count kept
growing each time, the Calculator program was started and stopped.

I feel there is some resource is not being freed. Has anyone run across this issue as well, or knows how to prevent the handle leak from occurring?

Below is a copy of the source code from the link above:

// Defines an event handler for general UI Automation events. It listens for
// tooltip and window creation and destruction events. 
#include <windows.h>
#include <stdio.h>
#include <UIAutomation.h>

class EventHandler:
    public IUIAutomationEventHandler
{
private:
    LONG _refCount;

public:
    int _eventCount;

    // Constructor.
    EventHandler(): _refCount(1), _eventCount(0) 
    {
    }

    // IUnknown methods.
    ULONG STDMETHODCALLTYPE AddRef() 
    {
        ULONG ret = InterlockedIncrement(&_refCount);
        return ret;
    }

    ULONG STDMETHODCALLTYPE Release() 
    {
        ULONG ret = InterlockedDecrement(&_refCount);
        if (ret == 0) 
        {
            delete this;
            return 0;
        }
        return ret;
    }

    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, void** ppInterface) 
    {
        if (riid == __uuidof(IUnknown)) 
            *ppInterface=static_cast<IUIAutomationEventHandler*>(this);
        else if (riid == __uuidof(IUIAutomationEventHandler)) 
            *ppInterface=static_cast<IUIAutomationEventHandler*>(this);
        else 
        {
            *ppInterface = NULL;
            return E_NOINTERFACE;
        }
        this->AddRef();
        return S_OK;
    }

    // IUIAutomationEventHandler methods
    HRESULT STDMETHODCALLTYPE HandleAutomationEvent(IUIAutomationElement * pSender, EVENTID eventID)
    {
        _eventCount++;
        switch (eventID) 
        {
            case UIA_ToolTipOpenedEventId:
                wprintf(L">> Event ToolTipOpened Received! (count: %d)\n", _eventCount);
                break;
            case UIA_ToolTipClosedEventId:
                wprintf(L">> Event ToolTipClosed Received! (count: %d)\n", _eventCount);
                break;
            case UIA_Window_WindowOpenedEventId:
                wprintf(L">> Event WindowOpened Received! (count: %d)\n", _eventCount);
                break;
            case UIA_Window_WindowClosedEventId:
                wprintf(L">> Event WindowClosed Received! (count: %d)\n", _eventCount);
                break;
            default:
                wprintf(L">> Event (%d) Received! (count: %d)\n", eventID, _eventCount);
                break;
        }
        return S_OK;
    }
};

int main(int argc, char* argv[])
{
    HRESULT hr;
    int ret = 0;
    IUIAutomationElement* pTargetElement = NULL;
    EventHandler* pEHTemp = NULL;

    CoInitializeEx(NULL,COINIT_MULTITHREADED);
    IUIAutomation* pAutomation = NULL;
    hr = CoCreateInstance(__uuidof(CUIAutomation), NULL,CLSCTX_INPROC_SERVER, __uuidof(IUIAutomation), (void**)&pAutomation);
    if(FAILED(hr) || pAutomation==NULL) 
    {
        ret = 1;
        goto cleanup;
    }
    // Use root element for listening to window and tooltip creation and destruction.
    hr = pAutomation->GetRootElement(&pTargetElement);
    if (FAILED(hr) || pTargetElement==NULL) 
    {
        ret = 1;
        goto cleanup;
    }

    pEHTemp = new EventHandler();
    if (pEHTemp == NULL) 
    {
        ret = 1;
        goto cleanup;
    }

    wprintf(L"-Adding Event Handlers.\n");
    hr = pAutomation->AddAutomationEventHandler(UIA_ToolTipOpenedEventId, pTargetElement, TreeScope_Subtree, NULL, (IUIAutomationEventHandler*) pEHTemp);
    if (FAILED(hr)) 
    {
        ret = 1;
        goto cleanup;
    }
    hr = pAutomation->AddAutomationEventHandler(UIA_ToolTipClosedEventId, pTargetElement, TreeScope_Subtree, NULL, (IUIAutomationEventHandler*) pEHTemp);
    if (FAILED(hr)) 
    {
        ret = 1;
        goto cleanup;
    }
    hr = pAutomation->AddAutomationEventHandler(UIA_Window_WindowOpenedEventId, pTargetElement, TreeScope_Subtree, NULL, (IUIAutomationEventHandler*) pEHTemp);
    if (FAILED(hr)) 
    {
        ret = 1;
        goto cleanup;
    }
    hr = pAutomation->AddAutomationEventHandler(UIA_Window_WindowClosedEventId, pTargetElement, TreeScope_Subtree, NULL, (IUIAutomationEventHandler*) pEHTemp);
    if (FAILED(hr)) 
    {
        ret = 1;
        goto cleanup;
    }

    wprintf(L"-Press any key to remove event handlers and exit\n");
    getchar();

    wprintf(L"-Removing Event Handlers.\n");

cleanup:
    // Remove event handlers, release resources, and terminate
    if (pAutomation != NULL) 
    {
        hr = pAutomation->RemoveAllEventHandlers();
        if (FAILED(hr))
            ret = 1;
        pAutomation->Release();
    }

    if (pEHTemp != NULL) 
        pEHTemp->Release();

    if (pTargetElement != NULL) 
        pTargetElement->Release();

    CoUninitialize();
    return ret;
}