[EWS][C#] DeleteItemFieldType on contact with email address of the logged user

My code use a generated proxy of the exchange web service, the server is exchange 2013.
I'm deleting the email address 1 of a contact with DeleteItemFieldType.

DeleteItemFieldType deleteItem =newDeleteItemFieldType();PathToIndexedFieldType path =newPathToIndexedFieldType();
path.FieldURI=DictionaryURIType.contactsEmailAddress;
path.FieldIndex=EmailAddressKeyType.EmailAddress1.ToString();
deleteItem.Item= path;

It was not working with exchange 2010  (email address was still in the contact information) but it does work well with exchange 2013, maybe too well.

I'm logged in OWA with the user test@test.com.
The contact in OWA has the same email address in EmailAddress1 (test@test.com)

If I delete this emailaddress from the contact information (with ews, with DeleteItemFieldType), I will have a weird reaction in OWA.
I will not be able to see the contact list of the user anymore, it will just show "No items were found."

If I search the contact (the one I removed the email address), I will have the error "the connection to the server failed"
If I search an other contact I will be able to have the result.

If I remove the email address of an other contact (and with an other email address as the one logged) I don't have any problem.

Is this normal?