I cannot duplicate that.

$ cat -vET ttt
#!/usr/bin/perl -apF$
split;$

$ perl -le 'print $]'
5.008

$ perl -MO=Deparse ttt
LINE: while (defined($_ = <ARGV>)) {
    our(@F) = split(" ", $_, 0);
    split(" ", $_, 0);
}
continue {
    print $_;
}
ttt syntax OK
$
[download]

Note that also the first argument of split is translated differently (and incorrect in your case). Perhaps you are dealing with an older version of Perl, which has even more bugs in B::Deparse?

Abigail