Windows' qmake.exe compiled with VC++ generates wrong Unix-style makefiles

The directory structure for the simple app is as follows:

/g4mgr/g4mgr.pro
/g4mgr/app/main.cpp

A "Makefile-from-windows-xcompile" generated using the Windows qmake with the following command line arguments:

-unix -spec C:\Qt\4.3.4\mkspecs\qws\linux-arm-g++

generates lines in the makefile that compare to the "native" equivalents as follows:

On Linux:

QMAKE_TARGET = g4mgr
DESTDIR =
TARGET = g4mgr

Windows "Native"

QMAKE_TARGET = g4mgr
DESTDIR = #avoid trailing-slash linebreak
TARGET = g4mgr.exe
DESTDIR_TARGET = g4mgr.exe

Windows X-compile:

QMAKE_TARGET =
DESTDIR = g4mgr/
TARGET = g4mgr/

The "TARGET" and "DESTDIR" from the Linux and Windows native build are essentially the same, whereas the Windows X-compile is quite different and causes an empty "g4mgr" sub-directory to be created.