After calling the method cell.getDateCellValue(), the program exits when the cell called upon does not have data of the type Date. Based on documentation, it should throw an exception instead of exiting the program.
The bug description seems to imply a call to System.exit() or similar, which seems very unlikely. The data-type checking exception code in HSSFCell.getDateCellValue() has been unchanged since svn r352092 (Feb-2002) Please re-open if this bug is observable in any recent version of POI