At least in debug mode the workbench does not close cleanly. A QT debug break point is triggered and the log console does not close correctly.
May be the last lines give a hint (I think the last two lines are also occuring independently from the statistics plugin, so it seems they can be ignored)
27.75 BlueBerry: Closing workbench... [11756:6212:0109/202039.113:ERROR:render_process_impl.cc(213)] WebFrame LEAKED 1 TIMES 28.34 core.mod.core.log: closing logfile (C:/Users/floca/AppData/Local/DKFZ/MITK Workbench_3594778661/data/9/mitk-0.log) [13144:2544:0109/202039.360:ERROR:process_win.cc(151)] Unable to terminate process: Zugriff verweigert (0x5) [13144:18824:0109/202039.366:FATAL:resource_scheduler.cc(1044)] Check failed: client_map_.empty().