The select event of the RowSelector component is explicitly fired in the RowSelectorRenderer during the APPLY_REQUEST_VALUES phase (see code below). This means that during the UPDATE_MODEL_VALUES phase all backing bean changes made by the select listener will be overwritten.

Code:
 if (rowSelector.getSelectionListener() != null) {
                     RowSelectorEvent evt = new RowSelectorEvent(rowSelector, rowIndex, b);
                     evt.setPhaseId(PhaseId.APPLY_REQUEST_VALUES);
 
                     rowSelector.queueEvent(evt);
 }
 

The event should better by fired in the INVOKE_APPLICATION phase e.g.

Code:
 if (rowSelector.getSelectionListener() != null) {
                     RowSelectorEvent evt = new RowSelectorEvent(rowSelector, rowIndex, b);
                     evt.setPhaseId(PhaseId.APPLY_REQUEST_VALUES);
 
                     rowSelector.queueEvent(evt);
 }

A similar issue applies to the ValueChangeEvent fired by the SelectInputText component. For some reasons the event is fired in the PROCESS_VALIDATIONS phase witch leads to the same problem as described above. Changes made at the backing bean will be overwritten in the UPDATE_MODEL_VALUES phase.