SyncFolderItems returns ErrorAccessDenied when permissions are "Limited Details" or "Availability only"

I'm using the SyncFolderItems web service against an Office 365 account.

I login to OWA as User A and share my primary calendar with User B.  When I share my calendar I can set the permission level to "Availability Only", "Limited Details", "Full Details", etc...

Now, as User B I want to use EWS to sync the calendar events that User A shared.

I call the SyncFolderItems web service as User B to get all the calendar events from User A using the SyncFolderId. 

If User A selected "Full Details" for the permission level SyncFolderItems works flawlessly.  However, if User A selected "Limited Details" or "Availability Only" for the permission level the web service will return "ErrorAccessDenied". I even tried setting the ItemShape to "IdOnly" (I was originally using "Default").

Is this a restriction of Exchange?  I would expect to still be able to sync the calendar items, but perhaps only be able to see certain fields in the response.

Here's the XML Request:

<?xml version='1.0' encoding='utf-8'?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
    <soap:Header>
        <t:RequestServerVersion Version="Exchange2010" />
    </soap:Header>
    <soap:Body>
        <SyncFolderItems xmlns="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
            <ItemShape>
                <t:BaseShape>IdOnly</t:BaseShape>
            </ItemShape>
            <SyncFolderId>
                <t:FolderId Id="AAMkAG..." />
            </SyncFolderId>
            <SyncState></SyncState>
            <Ignore></Ignore>
            <MaxChangesReturned>500</MaxChangesReturned>
        </SyncFolderItems>
    </soap:Body>
</soap:Envelope>

And the Response (again, only when the shared permission level was "Limited Details" or "Availability Only", it returns a successful response with "Full Details"):

<?xml version="1.0" encoding="utf-8"?>
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
    <s:Header>
        <h:ServerVersionInfo MajorVersion="15" MinorVersion="0" MajorBuildNumber="775" MinorBuildNumber="7" Version="V2_4" xmlns:h="http://schemas.microsoft.com/exchange/services/2006/types" xmlns="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" />
    </s:Header>
    <s:Body>
        <m:SyncFolderItemsResponse xmlns:m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:t="http://schemas.microsoft.com/exchange/services/2006/types">
            <m:ResponseMessages>
                <m:SyncFolderItemsResponseMessage ResponseClass="Error">
                    <m:MessageText>Access is denied. Check credentials and try again.</m:MessageText>
                    <m:ResponseCode>ErrorAccessDenied</m:ResponseCode>
                    <m:DescriptiveLinkKey>0</m:DescriptiveLinkKey>
                    <m:SyncState />
                    <m:IncludesLastItemInRange>true</m:IncludesLastItemInRange>
                </m:SyncFolderItemsResponseMessage>
            </m:ResponseMessages>
        </m:SyncFolderItemsResponse>
    </s:Body>
</s:Envelope>

Thanks,

- Sean