This condition was reported to SAS Support with the following resolution:
I'm able to reproduce this behavior using a query with the same structure. However, if I choose the option "Rows and columns as separate data columns" the results of the slice match with what I see in the query.
I've reported this behavior to our developers. Because of the nature of the problem, I've asked that they consider this for a hot fix on the current release of SAS Enterprise Guide.
It does appear that there was a scenario that was over looked by the developers. However if you include the default measure of your cube as part of your query, you can ensure that the data will be returned correctly. If you do not need the data in your resulting slice, you can use the Query Builder to drop that column. This should be addressed in a hot fix for the SAS Enterprise Guide 4.3 installation.