1) In demo.csv, modify the assignment to $data (by adding spaces around certain ',') to end up with:

$data = q{
  absmith , 1234567 , 20
  "aesmith, the other one" ,7635656 , DNS
  cat , dog , 22.2
  7637843 , dejones , 66.7
  rmwilliams , 288721 , 88
  help me,I'm trapped,in the marks system
  vtthan , 872829 , 94
};
[download]

One then gets the output intended by the author of demo.csv (I am not he)

Unknown entry format: [cat , dog , 22.2]
Unknown entry format: [help me,I'm trapped,in the marks system]
1234567 (absmith):      20
7637843 (dejones):      66.7
288721 (rmwilliams):    88
872829 (vtthan):        94
7635656 ("aesmith, the other one"):     ABSENT
[download]

But according to the documentation of Getopt::Declare, the lack of spaces around the ',' shouldn't matter and original demo.csv should also give the above output.