No, the date is not duplicated, NirSoft erroneously displays here the text fields of two different date/time tags having the same values ("Date Time Original" and "Date Time Digitized") which immediately follow each other in the file. Look at the "Value Length" column of 19 which gives only the first date, and when you click on the "DTOrig" row the hex viewer will also display only a single date.
Nevertheless, there is an issue with fpexif which does not write a trailing NULL byte after each string. NirSoft's ExifDataView seems to ignore the explicit length specification and seeks a trailing NULL byte after the date/time string. I looked into the EXIF specification and it clearly says for tag type 2 "ASCII An 8-bit byte containing one 7-bit ASCII code. The final byte is terminated with NULL."
The new fpexif revision on CCR does write a NULL byte, and NirSoft's viewer displays a single date now.