Limiting a coded observation query by an encounter type does not work right

I've got a patient that is showing up in two dimensions, but should only be showing up in one. The dimension is the "HOSPITAL ADMISSION WARD" concept from the LAST encounter type "HOSPITAL ADMISSION". The patient_id=50854 has only one "HOSPITAL ADMISSION" encounter, but is showing up in two wards; Internal Medicine and Adult Surgery when I run the report. It's probably getting confused with the same concept from the LAB form, where "HOSPITAL ADMISSION WARD" concept was Internal Medicine. The "HOSPITAL ADMISSION" encounter concept shows they were in the "Adult Surgery Ward". The "LAB" encounter concept shows they were in the Internal Medicine Ward.

I demonstrated the problem to Darius in a Skype call/screen sharing and we determined it to be a bug.

We need to try a unit test per Darius...
Encounter of type LookingFor on April 6, with obs value = NotLookingFor
Encounter of type NotLooking on April 10, with obs value = LookingFor

Query for:
last "LookingFor" in an encounter of type LookingFor
-> should have zero results.